WO1994029456A2 - Herpes simplex virus type-2 protease - Google Patents

Abstract

Protease activity associated with herpes simplex virus (HSV) type 2 was identified. The complete nucleotide and amino acid sequence of the protease was determined. The HSV-2 nucleic acid segment encoding the protease substrate ICP35 was also sequenced. Recombinant vectors and host cells for expressing the protease are also described.

Description

HERPES SIMPLEX VIRUS TYPE-2 PROTEASE

This application is a continuation-in-part of U.S. Serial No. 08/073,819, filed June 8, 1993, which enjoys common ownership and is incorporated herein by reference.

Technical Field

The present invention relates to the identification of a new enzyme in the area of herpes simplex virology. More particularly, it relates to the identification of a protease associated with herpes simplex virus type-2 (HSV- 2) protease, to nucleic acid sequences encoding such a protease, and to the expression of the protease by a host cell. The present invention also relates to the use of the proteolytic activity as a target for anti-viral therapy.

Background Human infections with herpes simplex virus (HSV) are ubiquitous throughout the world. The clinical course of HSV infections is extremely variable and primary infection is subclinical or mild enough to be unrecognized in a majority of cases. The major clinical conditions associated with HSV infections are gingivostomatitis, keratitis and conjunctivitis, vesicular eruptions of the skin, aseptic meningitis, encephalitis, genital tract infections, and neonatal herpes.

HSV falls into two distinct serotypes, designated type 1 and type 2 (HSV-1 and HSV-2, respectively). The HSV-1 genome specifies an abundant capsid protein (Gibson etal.,J. Virol. 13: 155-165 (1974)) and a set of genetically and immunologically related viral capsid proteins have been identified and designated infected-cell proteins 35 (ICP35) (Braun et al. J. Virol.49: 142-153 (1984)).

HSN-2, a member of the alphaherpesviridae subfamily of the herpesviridae family, has a variable host range, a short reproductive cycle, and the ability to establish a latent infection in the sacral ganglia (Roizman et al. Virology, 2τ\ά ΕΛ. New York: Raven Press 65: 1795-1841 (1990). The HSV- 2 virion is composed of a nucleoprotein core surrounded by a capsid, tegument, and a lipid membrane. These structural features are characteristic of all herpes viruses. The HSN-2 genome is approximately 150 kilobases in size. It consists of two components, the unique long (UL), and unique short (Us) regions (Braun et al. J. Virol 49: 142-153 (1984)). The genome encodes at least 70 proteins which are expressed during a productive infection; however, only a few are understood biologically (Roizman et al., supra). The acquisition of HSN-2 infection is usually the consequence of transmission via genital routes. Under these circumstances, virus replicates in the vaginal tract or on penile skin sites with seeding of the sacral ganglia (Whitley, Virology, 2nd Ed. New York: Raven Press 66: 1843-1887 (1990)). As with HSV-1- induced oral lesions, recurrent genital infections are the largest reservoir of herpes simplex virus type 2.

A major drawback in developing effective therapy against HSV-1 and HSV-2 has been the failure to discover viral-specific replicative mechanisms which can be blocked by antiviral agents. The ideal antiviral agent should interrupt viral replication at an essential step of the life cycle without significantly altering host-cell metabolism. While some progress has been made in controlling HSV infections through the use of drugs such as 5- fluorodeoxyuridine and acyclovir, no satisfactory treatment for HSV infections has been found. Consequently, improvement for antiviral therapy is needed in this area.

Maturation of herpes virus particles is believed to occur through the formation of a procapsid structure, which acquires DNA and an envelope to become an infectious virion (Whitley, supra, 1990; Roizman, supra, 1990). Proteases appear to be essential to the development of the capsid of the virus. Consequently, inhibiting protease action will lead to disruption of the lytic cycle of the virus. Thus, inhibitors of protease action are desirable targets for antiviral therapy.

Proteases have recently been identified for HSV-1 by Roizman et al. (EP 514830 published November 25, 1992, which is incorporated herein by reference) and for cytomegalovirus (CMV) by Gibson, et al. (WO 93/01291 published January 21, 1993, which is incorporated herein by reference). While there is some homology between these two proteases, it is well-established that alteration of even a single amino acid residue in an enzyme can profoundly influence its susceptibility toward inhibition by a given agent. Therefore, establishment of the primary structure for individual herpes proteases is a vital step in the discovery of agents which have inhibitory activity against a specific virus.

Up to the present time, a protease from HSV type 2 had not been identified. Summary of the Invention

The present invention provides a HSN type 2 protease. The amino acid sequence of the protease and the DΝA sequence, or degenerate equivalents thereof, which encodes the protease is shown in Figure 1.

The present invention further provides expression vectors capable of expressing HSN type 2 protease in a host cell. In particular, a DΝA segment encoding a HSN type 2 protease or a portion thereof is operably linked to suitable regulatory regions in a vector, whereby the vector is replicated and carried by the host cell. Recombinant host cells carrying said vectors are additionally provided.

Description of the Figures

Figure 1 shows the nucleotide and predicted amino acid sequences of the HSN-2 genomic region comprising the coding sequences of the protease gene and ICP35 protein. The HSN-2 gene comprises a DΝA sequence beginning at nucleotide 211 and extending through nucleotides 951-1120; this range is flexible and is meant to denote all portions of the sequence which encode for protease activity. The open reading frame for the ICP35, the substrate for the protease, comprises the amino acid sequence presented in Figure 1 between nucleotides 1124 and 2119.

Figure 2 is a schematic representation of the HSN gene showing the expression cassettes used in the examples.

Figure 3 shows the SDS-PAGE for the expression and self-processing of HSN-2 protease-CKS fusion protein in E. coli.

Figure 4 shows the SDS-PAGE for the expression and self-processing of HSN-2 protease translationally coupled to CKS in E. coli.

Figure 5 is a Western Blot of HSN-2 protease expression and self- processing in E. coli. Figure 6 is a schematic illustration of the construction of plasmid pSSPIl as described in Example 13.

Figure 7 shows the SDS-PAGE for the expression and self-processing of HSN-2 protease/ICP35 translationally coupled to CKS in E. coli.

Figure 8 is a Western Blot of HSN-2 protease expression and self- processing in S. cerevisiae. Figure 9 shows the SDS-PAGE for the expression and self-processing of HSN-2 protease in Sf9 cells.

Figure 10 is a Western Blot of HSN-2 protease expression and self- processing in Sf9 cells. Figure 11 shows the SDS-PAGE for the expression and self-processing of HSN-2 protease in Baculovirus-infected Trichoplusia ni larvae.

Figure 12 is a Western Blot of HSN-2 protease expression and self- processing in Baculovirus-infected Trichoplusia ni larvae.

Detailed Description Definitions

The following terms are defined as used herein: "CKS" refers to CTP:CMP-3-deoxy-D- ann<3-octulosonate cytidylyl transferase, also known in the art as CMP-KDO synthetase or CKS, an enzyme derived from Escherictiia coli (E. coli), according to methods known in the art. "DΝA expression vector" is any autonomous element capable of replicating in a host independently of the host's chromosome, after additional sequences of DΝA have been incorporated into the autonomous element's genome. "Gene" is a segment of DΝA, a portion of which codes for a specific polypeptide or RΝA molecule.

"ICP35" refers to a set of genetically and immunologically related viral capsid proteins identified with the HSN-1 and -2 genomes.

"Promoter" is a DΝA sequence generally described as the 5' region of a gene, located proximal to the start codon. At the promoter region, transcription or expression of an adjacent gene is initiated. This is referred to as the transcription initiation site. At the promoter region may be a sequence of nucleotides that interacts as a control over the expression of any operably linked structural gene or genes. "Operably linked" is a term for the control exerted by the promoter over the initiation of expression of the polypeptide encoded by a structural gene.

"Open reading frame" (ORF) is a DΝA sequence containing a series of triplets coding for amino acids without any termination codons. Sequences of this type are potentially translatable into a protein. "Protease" refers to a proteolytic activity and the corresponding encoding nucleic acid sequences which are capable of cleaving a herpes virus assembly protein precursor. The HSN-2 protease gene of the present invention comprises a DΝA sequence beginning at nucleotide 211 and extending through nucleotides 951-1120; this range is flexible and is meant to denote all portions of the sequence which encode for protease activity.

"Transcription initiation site" is a DΝA sequence of a promoter to which RΝA polymerase binds, thereby initiating transcription of succeeding codons in a 5' to 3' direction. "Transcription terminator" is a DΝA sequence at the end of the transcript that causes RΝA polymerase to terminate transcription.

"UL26" refers to that part of the HSN-2 genome believed to encode the protease and the adjoining ICP35 gene.

Identification And Molecular Cloning Of The HSN-2 Protease

The present invention relates to the discovery of a new viral protease encoded by HSN type 2. The genome of HSN-2 is approximately 150 kilobases in size. Unlike HSN-1, much of the genomic DΝA of HSN-2 has not been sequenced. And, to date, only a few analogous genes related to HSN-1 have been identified within the HS V-2 genome. The proteins expressed by these genes which have been identified to date include thymidine kinase, glycoproteins C & D, DΝA polymerase and alkaline exonuclease. To determine whether a novel protease similar to the protease encoded by the UL 26 gene of HSN- 1 could be identified within the HSN-2 genome, a strategy was devised which utilized the nucleic acid segment encoding the HSN-1 protease gene as a tool for detecting homologous sequences within the HSN-2 genome. HSN-2 DΝA was isolated from Nero cells infected with HSV-2 strain G using the procedure of Straus et al. J. Virol. 40: 516-525 (1981). Approximately 10 μg of DΝA was digested with -BαmHI enzyme and separated on a 1% TBE gel. For the hybridization and Southern blot analysis, the gel was stained with ethidium bromide, photographed, and placed on a southern blotting apparatus for transfer to nitrocellulose. A nick-translated 32p.ι_abeled probe of the HSV-1 protease gene was added to the blot and left to hybridize overnight. After extensive washing, the blot was subjected to autoradiography for 30 minutes. A single band corresponding to approximately 4.0 kilobases in size was visualized. This segment of DNA contained the putative HSV-2 protease coding sequence. In order to clone the protease gene from the HSV-2 genome, a shotgun cloning procedure was employed which utilized the -BαmHI-digested HSV-2 genome randomly cloned into the plasmid vector pUC19. Transformed bacterial colonies from the ligated pUC19 vector were screened by DNA-DNA colony hybridization. Five HSV-2-specific DNA clones containing the protease gene were identified by hybridizing the nick- translated HSV-1 protease DNA probe to nitrocellulose. For verification of the HSV-2 DNA sequence contained within pUC19, positive bacterial colonies were picked from a replica plate, grown, and plasmid DNA extracted from them. A BamΗI digest of the DNA demonstrated that each clone contained the 4.0 kilobases DNA fragment encoding the HSV-2 protease gene. To further define a fragment encoding the HSV-2 protease, the 4.0 kilobases fragment was subjected to several different restriction digests and Southern blot analyses. A single 1.5 kilobases BaniHl-Saπ. fragment containing the protease gene was identified by Southern blot hybridization and subcloned into pUC19. This plasmid has been designated pH2Pro which contains the entire HSV-2 protease coding sequence.

DNA Sequence of the HSN-2 Protease Coding Sequence

In order to determine the DΝA sequence of the HSN-2 protease coding sequence, the -δαmHI-Sύ-ZI fragment was cloned into M13mpl8 and M13mpl9 phage RF vectors for single-stranded DΝA sequence analysis. Several phage clones from transformed mpl8 and mpl9 plates were picked and sequenced through the first 100 bases to determine the correct orientation for sequence analysis. One mpl9 clone was correctly oriented and became the focus of the DΝA sequencing analysis. Approximately 1900 bases of the protease gene have been sequenced from the Banύr→l-SaU. mpl9 clone.

The complete coding sequence for the HSV-2 protease is shown in Figure 1 between nucleotides 211 -951. The promoter region for the HSN-2 protease has also been isolated and maps between positions 1-210 as shown in Figure 1. The coding sequence for ICP35 is between nucleotides 1126-2119.

The sequence can be derived from plasmid pH2proA (which contains the entire HSN-2 protease coding sequence along with flanking promoter/regulatory sequences and partial ICP35 coding sequences) or pH2proB (which contains the remaining coding sequence for the assembly protein ICP35). Plasmids pH2proA and pH2proB were deposited on April 26, 1993 at the Agricultural Research Service Patent Culture Collection, Peoria, Illinois and have the accession numbers NRRL B-21185 and NRRLB-21186, respectively. The nucleic acid sequences of the present invention may include a sequence or portion thereof as illustrated in Figure 1. For example, the sequence may be either smaller or larger than those illustrated in Figure 1 as long as the nucleic acid segment encodes a functional equivalent of the protease.

Protein Sequence of the HSV-2 Protease

The HSV-2 protease coding region encodes a polypeptide of approximately 247 amino acids which has the amino acid sequence presented in Figure 1 between nucleotide 211 and 951. It is understood that the size of the protease may be smaller or larger than this range as long as the protein fragment retains its biological or functional activity. In addition, any herpes protease containing at least 70% homology, and preferably 90% homology, to any contiguous stretch of ten or more amino acids presented herein which is isolated from a HSV-2 source is also intended to be within the scope of the present invention. This homology is determined by any of the available sequence analysis software packages, such as that available from DNAstar, Intelligenetics, the Genetics Computer Group of the University of Wisconsin, and the like.

The DNA and deduced amino acid sequence of a preferred HSV-2 protease and ICP35 are provided in Figure 1. In addition to the amino acid sequence shown, any modification of the protein which does not destroy the activity of the protein is specifically included. These modifications include, but are not intended to be limited to, oxidation, reduction, and the like. In addition, modifications to the primary structure itself by deletion, addition, or alteration of the amino acids incorporated into the sequence during translation which can be made without destroying the activity of the enzyme fall within the contemplated scope of the present invention.

Expression of Recombinant HSN-2 Protease

In general terms, the production of a recombinant form of HSN-2 typically involves (a) isolating a DΝA that encodes the mature enzyme; (b) placing the recovered coding sequence in operable linkage with suitable control sequences in a replicable expression system; (c) transforming a suitable host with the vector; and (d) culturing the transformed host under conditions to effect the production of the recombinant HSN-2 protease.

The control sequences, expression systems, and transformation methods are dependent on the type of host cell used to express the gene.

Prokaryotes are most frequently represented by various strains of Escherichia coli. However, other microbial strains may also be used, for example, Bacillus subtilis, various strains of Pseudomonas, or other bacterial strains. In such prokaryotic systems, plasmid vectors that contain replication sites and control sequences derived from a species compatible with the host are used. For example, E. coli is typically transformed with derivatives of pBR322, a plasmid derived from an E. coli species described by Bolivar, et al, Gene 2: 95 (1977). Many recombinant proteins have also been expressed in cultured insect cells by using a baculovirus vector which contains the gene of interest under the control of the polyhedrin promoter (for review, see Luckow, N. A. & Summers, M. D. (1988) BioTechnology 6, 47-55). Although the activity of the polyhedrin promoter is quite high in insect cells, it appears to be even higher in insect larvae (Shieh, T. R. & Bohmfalk, G. T. (1980) Biotechnol. Bioeng. 22, 1357-1375). The larval expression system is often an inexpensive alternative to the cell culture expression system for expression of milligram quantities of foreign proteins (Price, P. M., Reichelderfer, C. F., Johansson, B. F., Kilboume, Ε. D., & Acs, G. (1989) Proc. Natl. Acad. Sci. 86, 1453-1456; Medin, J. A., Hunt, L., Gathy, K., Evans, R. K., & Coleman, M. S. (1990) Proc. Natl. Acad. Sci. 87, 2760-2764) because the larval expression system circumvents the need for specialized large-scale tissue culture facilities and expensive tissue culture media. Infection of insect larvae with baculovirus can be achieved by injection of the virus into the larval hemolymph (Medin, et al., 1990, supra), or by oral ingestion (Price, et al., 1989, supra). It has been reported that infection of larvae by the oral route with recombinant viruses lacking the polyhedrin protein can be improved by coinfection with wild- type nuclear polyhedrosis virus (Price, et al., 1989, supra.). In some of the examples described below, infection of cabbage looper larvae was achieved using recombinant virus alone as well as with a mixture of recombinant and wild type baculoviruses. The present invention also provides suitable vectors for the expression of the HSN-2 protease. The construction of suitable vectors containing the desired coding and control sequences employs standard ligation and restriction techniques that are well understood in the art. Site-specific DΝA cleavage is performed by treating the DΝA with the suitable restriction enzyme under conditions that are generally well-understood in the art.

With reference to a vector of the present invention, any selectable marker may be used which is functional in E. coli or other selected host and allows cells transformed with a vector of the present invention to be distinguished from cells not so transformed. A gene that provides a dominant selectable marker for antibiotic resistance in E. coli is such a selectable marker. The gene for ampicillin resistance is especially preferred. Other DΝA segments which confer resistance to other antibiotics, including apramycin, tylosin, picromycin, oleandomycin, viomycin, neomycin, tetracycline, chloramphenicol, hygromycin and the like, can be used either as replacements of, or in addition to, the drug resistance segment described herein.

A transforming DΝA according to the present invention may include elements for its selection and replication in bacteria, especially E. coli, whereby production of large quantities of DΝA by replication in bacteria will be facilitated. In this regard, a preferred DΝA of the present invention is a plasmid which includes a segment comprising the origin of replication and ampicillin resistance gene or fragment thereof of plasmid pBR322.

Yeast offer an attractive alternative host system to E. coli. For example, a typical yeast expression vector will comprise (i) a yeast selective marker, (ii) a yeast origin of replication and (iii) yeast promoter and terminator sequences positioned relative to a unique restriction site in such a way that expression of HSN-2 protease may be obtained. For example, a non-fusion vector cassette and a fusion vector cassette containing eleven amino acids from the amino terminus of the sorbitol dehydrogenase (SDH) polypeptide as described in US. Serial Number 07/998,226 filed December 30, 1992 entitled "Enhanced Yeast Expression Using Regulatory Control Sequences From Yeast Sorbitol Dehydrogenase Gene" which is incorporated by reference herein, may be used. Both cassettes may be inserted into a 30 copy yeast plasmid containing the yeast TRP1 gene as a selectable marker and 2 micron origin of replication. Any yeast replication origin known in the art may be used to construct the vector. For example, the replication region of the natural yeast plasmid 2 micron can be employed. This plasmid is cryptic in that it confers no readily detectable phenotype and is present in about 100 copies per cell. For example, S. cerevisiae, a common laboratory strain of yeast used for its low toxicity and well known genetic characteristics can be used. This strain is readily cultivated on a large scale. The recombinant DNA encoding the HSV-2 protease of the present invention is placed under the control of transcriptional and translation initiation and termination regulatory sequences of the alcohol dehydrogenase I gene (as described in the Example section) and used to express HS V-2 in any yeast cell capable of transformation, including, but not limited to, yeast mutants that alter regulation, and the like.

The vast majority of yeasts can be cultivated under relatively uniform conditions utilizing common laboratory media and methods known in the art As would be understood by one skilled in the art, the typical growth requirements of yeast comprise an organic carbon compound for carbon and energy, organic or inorganic nitrogen for the synthesis of polypeptides and nucleic acids, various minerals, and a mixture of vitamins. Such growth requirements are met by yeast nitrogen base (YNB), a chemically defined medium which contains a number of trace elements, vitamins, trace amounts of amino acids to stimulate growth, and the principal minerals potassium phosphate, magnesium sulfate, sodium chloride, and calcium chloride. The nitrogen source is ammonium sulfate. The desired carbon source is added at a concentration of from between about 0.5% and between about 3%. The pH range of the medium is usually from between about pH 3.0 and about pH 8.0, preferably from between about pH 4.5 and about pH 6.5.

In the examples that follow, segments of the HSV-2 viral genome including all or portions of the UL26 gene, believed to encode the protease and the adjoining ICP35 gene, are cloned into a series of vectors designed to give efficient expression in E. coli, S. cerevisiae or insect cells. In each case, the segments to be cloned are amplified from the viral genome employing the polymerase chain reaction (PCR) as described in US. Patents 4,883,195 and 4, 883,202, the entire disclosures of which are incorporated herein by reference. Since PCR often introduces changes into the amplified sequence, the segments of UL26 amplified are sequenced after cloning into the respective vectors to determine that they match the sequence obtained from pH2proA and pH2proB, which carry the unamplified UL26 gene derived from genomic HSN-2 DΝA. Segments of UL26 cloned include the first 247 amino acids, from the Ν-terminus to the site believed to be cleaved by the HSN-2 protease or the first 306 amino acids, from the Ν-terminus to the methionine residue which is believed to correspond to the start of the ICP35 gene. Expression of the protease as part of an operon wherein the protease gene is downstream of a highly expressed gene is also described. In another example, expression of the entire UL26 gene, comprising the protease and adjacent ICP35 segments in yeast is described.

Method of Screening Candidate Antiviral Inhibitor Compounds Using HSN-2

PrQtease

The protease of the present invention is useful in a screening method for identifying potential herpes viral protease inhibitor compounds, also known as "candidate antiviral inhibitor compounds". It is contemplated that this screening technique will prove useful in the general identification of any compounds that will serve the purpose of inhibiting HSN-2 protease. It is further contemplated that useful compounds in this regard will not be limited to proteinaceous or peptidyl compounds but may include synthetic organic compounds which are non-peptidyl in nature and which will be recognized and bound by the protease, and serve to inhibit the enzyme through a tight binding or other chemical interaction. The use of such inhibitors to block the action of the protease will serve to treat or alleviate an HSN-2 infection. Inhibitors of HS V-2 protease will be useful by themselves or in conjunction with other herpes therapies.

Thus, in these embodiments, the present invention is directed to a method for determining the ability of a candidate compound to inhibit HS V-2 protease, the method comprising: obtaining a composition comprising HS V-2 protease that is capable of cleaving an appropriate substrate in a reaction mixture; mixing a candidate compound with the protease and suitable substrate; and determining whether the candidate compound inhibited the protease from cleaving the substrate.

An important aspect of the candidate compound screening assay is the ability to prepare a protease composition in a relative purified form. This is an important aspect of the candidate compound screening assay in that without at least a relatively purified preparation, one will not be able to assay specifically for HS V-2 protease inhibition, as opposed to inhibition by extraneous substances in the assay. In any event, the successful expression of the recombinant HS V-2 protease now allows for the first time the ability to identify new compounds which can be used for inhibiting this herpes-related protein.

To perform the assay, it will be necessary to measure the activity of the relatively purified HS V-2 protease in the absence of the assayed candidate compound relative to the activity in the presence of the candidate compound in order to assess the relative inhibitory capability of the candidate compound.

Examples

Materials and Methods

Standard methods were employed for restriction endonuclease digestion, DNA ligation, plasmid preparation, E. coli transformation and other DNA manipulation techniques and for SDS-PAGE and Western blotting as described by Maniatis et. al., Molecular Cloning, A Laboratory Manual, (2nd Ed.) Cold Spring Harbor, N.Y. (1989). Plasmid DNAs used for co-transfection of insect cell cultures were prepared by equilibrium centrifugation in cesium chloride gradients according to Maniatis et. al., supra. DNA fragments were recovered from low melting temperature agarose (SeaPlaque Agarose, FMC, Rockland, ME.). Plasmid preparations were done using the Magic DNA preparation systems by Promega. Insertion of DNA fragments into pUC18 or its derivatives, pKB130, pJO201, etc. often employed the use of X-gal as a color reagent to screen for the presence of inserts.

The standard PCR mixture contains the following components: 50 ng HSV-2 genomic DNA, 20 mM Tris-HCl pH 8.3, 1.5 mM MgCl2, 50 mM KC1, 0.2 mM dATP, dCTP, dTTP and dGTP, 0.4 pmol/ml each primer, 10% formamide, 2% glycerol and 1 U Taq DNA polymerase in a 50 μl reaction. The standard PCR conditions can be varied to include: 50 ng HSV-2 genomic DNA, 20 mM Tris-HCl, pH 8.8 10 mM KC1, 10 mM ammonium sulfate, 6 mM magnesium sulfate, and 0.1% Triton X-100, 0.2 mM dATP, dCTP, dTTP and dGTP, 0.4 pmol ml each primer. The variation can also include 0.1 mg ml acetylated BSA, 10% formamide, and 2% glycerol. A commercially available thermostable polymerase such as Taq DNA polymerase {Thermus aquaticus), Vent DNA polymerase, or Tth DNA polymerase (Thermus thermophilus) must also be added. Cycling temperatures and times are described for each application. Growth of E. coli in L broth and transformation of plasmid DNA into E. coli is done as described by Maniatis et al., supra. General methods used in the manipulation of yeast are described by

Sherman et al., Methods in Yeast Genetics; A Laboratory Manual, Cold Spring Harbor, N.Y. (1983). Minimal medium contain 0.67% yeast nitrogen base and 2% glucose. Amino acids are added according to Sherman et al., supra. Transformation of yeast is described by Percival et al., Anal. Biochem. 163:39 (1987). Transformants containing plasmids derived from pVTIOO-U and it's derivatives were grown selectively at 30°C for 48 hrs in minimal liquid medium containing 2% glucose as the carbon source. For SDS-PAGΕ, cell pellets from 10 ml cultures were first washed with 3 ml of glass-distilled water, resuspended in 1 ml of Tris pH 7.4, 2 mM ΕDTA, 1 mM PMSF and disrupted with glass beads by vortexing for 2 min. An aliquot of the lysate was mixed with an equal volume of 2x sample buffer (125mM TRIS pH 6.8, 4% SDS, 20% glycerol, 1.4M β-mercaptoethanol and 0.004% Bromo Phenol Blue). 20μl aliquot were analized on SAS-PAGΕ. Expression of the HS V-2 Protease is determined by Western Blot analysis. To prepare soluble protein extracts of Sf9 insect cells, 2 x 10^ cells were plated in 25 cm^ flasks and infected with 1 ml of culture fluid containing recombinant virus plus 4 ml of fresh media. Infections were allowed to proceed for three days, after which time cells were harvested by low speed centrifugation and washed once with phosphate buffered saline. Cells were then resuspended in 100 ml of hypotonic lysis buffer (10 M Tris pH 7.4, 10 mM NaCl, 1.5 mM MgCl2) and incubated on ice with occasional vortexing for 20 minutes. The extract was then pelleted in a microfuge for 2 minutes to remove any insoluble material and used for SDS-PAGE.

Cabbage looper moths and larvae (Tric→hoplusia ni ) were reared according to the method of Guy, R., Leppla, N., Rye, J., Green, C, Barrette, S. & Hollien, K. (1985) in "Handbook of Insect Rearing, Vol. II", edited by P. Singh and R. Moore, Elsevier, Amsterdam. Adults were maintained in environmental growth chambers at 28 °C, 80% relative humidity, with a 14 hour photophase and fed a 10% sucrose solution. Oviposition occurred on paper toweling which was wrapped around the wire mesh cages. The egg laden toweling was surface sterilized with dilute formalin and rinsed thoroughly with water. Eggs were incubated at 27 °C and 50% relative humidity in sealed 2-liter plastic containers for two days. Newly hatched larvae were transferred onto the surface of freshly made, solidified insect diet (a wheat germ/soy flour based agar diet) in 30 ml plastic cups with lids. Details regarding the formulation and preparation of semisynthetic diets for cabbage looper larvae can be found in Guy, et al., 1985, and in Medin, et al., 1990).

Reagents and Enzvmes

Media for growth of bacteria and yeast were purchased from Difco, Detroit, Michigan. All enzymes were purchased from New England BioLabs, Beverley, Massachusetts; Bethesda Research Laboratories (BRL), Gaithersburg Maryland. Zymolyase 60T was purchased from Miles Laboratory, Elkhart, Indiana. Nick Translation kit and other reagents for Nick translations were obtained from Amersham Corporation, Arlington Heights, Illinois. Thermostable polymerases were purchased from New England Biolabs, Beverley, MA, Epicentre Technologies, Madison, WI, Pharmacia P-L Biochemicals, Milwaukee, WI, and Promega, Inc. Factor Xa was purchased from Boehringer-Mannheim, Indianapolis, IN and used according to manufacturer's specifications.

Host Cells Cultures and Vectors for Expression.

Vero cells were grown in Dulbecco's Modified Eagle Medium (DMEM) supplemented with 10% Fetal Calf Serum. HSV-2 strain G was obtained from the American Type Culture Collection (ACT VR-734). Viral stocks were grown and titered on Vero cells.

E. coli strain XLl-Blue and DH5α competent cells for transformation were purchased from Stratagene and BRL, respectively. Saccharomyces cerevisiae strain YJO ( ura3-52 leu2-3,l 12 gal4Δ gal80Δ) was obtained from Dr. B. Kohorn, Duke University, Durham, NC. Yeast vector pVTIOO-U (which contains the yeast alcohol dehydrogenase 1 [ADH1] expression cassette, a yeast URA3 selectable marker and the yeast 2μ origin of replication; Gene 52, 225-233, 1987) was obtained from Dr. D. Thomas, Biotechnology Research Institute, National Research Council of Canada, Montreal, Que., Canada. The Baculovirus expression system, including Baculogold insect virus, expression vector pVL1392, Sf9 insect cells, and TMN-FH serum- supplemented culture media were obtained from Pharmingen, San Diego, California. Handling of tissue culture cells and propagation of recombinant virus were performed according to the suppliers specifications as instructed in the accompanying manual by Gruenwald et. al., Baculovirus Expression Vector System: Procedures and Methods Manual, 2nd Ed. Sf9 insect cell cultures were maintained in 75 cm^ tissue culture flasks at 27 °C. Cells were fed with fresh TMN-FH media every 2 to 3 days and split 1:5 once per week. Cells were split into fresh cultures 1 or 2 days prior to their use in transfections or infections to insure healthy log phase growth. All viral stocks were stored at 4 °C. and protected from exposure to light.

Synthesis and purification of oligonucleotides All oligonucleotides were synthesized on an Applied Biosystems model

380A DNA synthesizer at the Molecular Biology Services Facility, Abbott Laboratories. Crude oligonucleotide preparations were purified by HPLC.

DNA Sequence Analysis For DNA sequencing of positive colonies containing the putative HS V-

2 protease and ICP35 genes, -BαmHI-Sal I, BarriHL, and Sal I fragments were cloned into M13mpl8 and M13mpl9 phage RF vectors for single-stranded DNA sequence analysis. Single-stranded DNA sequencing was done using the United Biochemical Sequenase Kit®. DNA sequencing was done from plasmid DNA by primer walking using alkaline denaturation, the USB

Sequenase kit and protocols, and ³³P-dATP (DuPont-NEN, Wilmington, DE.). In order to resolve sequencing difficulties due to high G-C DNA, deaza nucleotides and altered reaction conditions were employed. The labeling reactions were done on ice for 5-10 minutes and the termination reactions were done at 42 °C.

Example 1 Preparation of HS V-2 nucleocapsids and viral DNA

HSV-2 DNA was isolated from Vero cells infected with HSV-2 (G) at a multiplicity of 0.001 plaque-forming units per cell using the procedure of Straus et al. supra (1981). Cells were collected, spun down at low speed (3000 rpm) and resuspended in IX lysis buffer [0.5% NP-40, 3.6 mM CaCl2, 5 mM magnesium acetate, 125 mM KC1, 0.5 mM EDTA (pH 7.5), 6 mM β- mercaptoethanol, 0.5% deoxycholate]. Cell lysate was extracted one time with freon by shaking for 1 minute and centrifuging at 1000 rpm for 10 minutes at 4°C. The aqueous phase was removed and layered onto a discontinuous gradient of 5% and 40% glycerol in IX lysis buffer and spun at 33,000 rpm for 45 minutes. After spinning, cell pellets were taken up in 2X STE [0.1M Tris- HCl pH 7.5), 20 mM EDTA, 2% SDS], proteinase K was added to a final concentration of 200 mg ml and incubated at 50°C for 30 minutes. Viral DNA was gently extracted by washing one time with phenol, one time with a phenol- chloroform mixture, and one time with a chloroform/isoamyl alcohol mixture. The upper aqueous phase containing HS V-2 DNA was carefully removed with a wide-bore pipette and precipitated in three volumes of ethanol at -20°C.

Example 2 Southern Blot analysis of HSV-2 DNA

Southern blotting and hybridization was done essentially as described by Maniatis et al. supra (1982). Approximately 10 μg of HSV-2 DNA was digested with the restriction enzyme BamHI and separated by gel electrophoresis on a 1% TBE agarose gel for 3 hours at 100V. After electrophoresis, the gel was stained with ethidium bromide, photographed, and placed in a Southern blotting unit for transfer to nitrocellulose. The DNA was depurinated for 5 minutes in a solution of 0.25N HC1, denatured in a solution of 1.5M NaCl and 0.5M NaOH, and neutralized. A nick-translated probe derived from the HSV-1 protease sequence was used for the hybridization. The hybridization was left overnight, then washed in 2X SSC [300 mM NaCl, 0.90 mM sodium citrate, 3 mM EDTA, pH 7.0]/0.1% SDS for a total of 30 minutes, dried, and exposed to X-ray film. For similar blots, a BamHI-Sal I restriction digest was used to generate different restriction digest patterns. Generation HSV-2 genomic libraries

For the generation of an E. coli derived library of HS V-2 DNA genomic fragments, HS V-2 DNA was subjected to -BαmHI, Sal I, and -BαmHI- Sal I digests, and the resulting digested DNA was cloned into the pUC19 vector enzymatic restriction as described in Straus et al. supra (1981). The ligated DNA was used to transform competent JM109 cells and colonies were picked to generate an HS V-2 derived genomic library. DNA-DNA colony hybridization

In all cases, colony hybridization was used to identify HS V-2-protease specific clones in pUC19. Colonies derived from the genomic library were replica-plated onto nitrocellulose. The bacterial colonies were lysed and prepared as described in Maniatis et al, supra, (1982). After neutralization, the colony blot was transferred onto 3 MM paper and baked at 80°C for 2 hours. Colony blots were prehybridized for 4 hours, then a nick-translated probe derived from HSV-1 protease strain F was denatured and added to the prehybridization solution and left to hybridize overnight. After washing, the blot was dried and autoradiographed. Positive colonies were picked, grown, and subjected to restriction digest analysis.

Example 3

Identification and Molecular Cloning of the HSV-2 Protease

HSV-2 DNA was isolated from Vero cells infected with HS V-2 strain G as described in Example 1, above. Approximately 10 μg of DNA was digested with BamHL enzyme and separated on a 1% TBE gel. For the hybridization and Southern blot analysis, the gel was stained with ethidium bromide, photographed, and placed on a southern blotting apparatus for transfer to nitrocellulose. A nick-translated 32p-i beled probe of the HSV- 1(F) protease gene was added to the blot and left to hybridize overnight. After extensive washing, the blot was subjected to autoradiography for 30 minutes. A single band corresponding to approximately 4.0 kilobases in size was visualized. This segment of DNA contained the putative HS V-2 protease gene.

The protease gene was cloned from the HS V-2 genome employing a shotgun cloning procedure utilizing the -δα/nHI-digested HS V-2 genome randomly cloned into the plasmid vector pUC19. Transformed bacterial colonies from the ligated pUC19 vector were screened by DNA-DNA colony hybridization. Five HS V-2-specific DNA clones containing the protease gene were identified by hybridizing the nick-translated HSV-1 protease DNA probe to nitrocellulose. For verification of the HS V-2 DNA sequence contained within pUC19, positive bacterial colonies were picked from a replica plate, grown, and plasmid DNA extracted from them. A -SαmHI digest of the DNA demonstrated that each clone contained the 4.0 kilobases DNA fragment encoding the HS V-2 protease gene. To further define a fragment encoding the HSV-2 protease, the 4.0 kilobases fragment was subjected to several different restriction digests and Southern blot analyses. A single 1.5 kilobases BamHI- Sal I fragment containing the protease gene was identified by Southern blot hybridization and subcloned into pUC19 . Further restriction analyses also revealed a pUC19-derived clone containing a 1.9 kilobases Sal I fragment with additional coding sequences. This plasmid has been designated pH2ProA which contains the entire HS V-2 protease coding sequence along with flanking promoter/regulatory sequences and partial ICP35 coding sequences.

To identify the 3' end of the coding sequence of the ICP35 assembly protein, a similar DNA-DNA colony hybridization was done using existing ICP35 sequences as a probe to identify the full-length ICP35 gene. Several positive clones derived from an HS V-2 Ba HL library were identified and sequenced. This plasmid has been designated pH2ProB which contains the remaining coding sequence for the assembly protein ICP35. Together, both plasmids pH2ProA and pH2ProB contain the full-length HS V-2 protease and assembly protein ICP35.

Example 4

DNA Sequence of the HSV-2 Protease Gene

In order to determine the DNA sequence of the HS V-2 protease gene, the BamHL-Sal I fragment was cloned into M13mpl8 and M13mpl9 phage RF vectors for single-stranded DNA sequence analysis. Several phage clones from transformed mpl8 and mpl9 plates were picked and sequenced through the first 100 bases to determine the correct orientation for sequence analysis. One mpl9 clone was correctly oriented and became the focus of the DNA sequencing analysis. In addition, both the 1.9 kilobases SalL fragment derived from pH2ProA and the BamHL fragment derived from pH2ProB were cloned into M13mpl9 for sequencing.

Example 5 Expression of HSV-2 Proteased -247) as a CKS Fusion Protein

A cassette system was utilized to clone portions of the UL26 gene for expression of the protease gene in E. coli as shown in Figure 2. The cassettes were PCR amplified from HS V-2 genomic DNA utilizing primers with non- homologous tails and appropriate restriction sites for cloning. Part A contains the 5' MET ATG of protease up to a unique AccL site at nucleotide 177. Part B contains the AccL site at nucleotides 177 through 741 which encodes the protease gene up to the cleavage site at amino acid 247. Part C contains nucleotides 725 to nucleotides 921 which encodes the 3' end of the protease from a unique AflLTL site through to the start of the ICP-35 portion of the molecule.

Construction of plasmid pAlB6 was acheived by PCR amplification of parts A and B and cloning into the expression vector pJO201 resulting in the expression of C-terminally fused HSV-2 protease(l-247).

PCR was accomplished using a mixture containing 50 ng HSV-2 genomic DNA, 20 mM Tris-HCl pH 8.8, 2 mM MgSO4, 10 mM KC1, 10 mM (NH4)2SO4, 0.2 mM dATP, 0.2 mM dCTP, 0.2 mM dTTP, 0.2 mM dGTP, 0.4 μM each oligonucleotide primer, 10% formamide, 2% glycerol and 1U Vent DNA polymerase in a 50 μl reaction. Vent was added after heating the mixture at 95 °C for 1 minute. Five cycles were performed as follows: denaturation at 95 °C for 30 sec; annealing at 44 °C for 30 sec; extension at 72 °C for 45 sec which were followed by 25 cycles as follows: denaturation at 95 °C for 30 sec, annealing at 54 °C for 30 sec, extension at 72 °C for 45 sec. A final extension period of 10 min at 72 °C completed the reaction. All PCR products were verified by DNA sequencing.

The 5' (upstream) PCR primer for part A was: 5-TAGATGAATICΑTAGAAGGTα3TΑT^^ TrAG GGaXXnC-n-XXXX-L^CGGG-S'. It has an EcoRI site for cloning and a Factor Xa cleavage site at the CKS/HS V-2 junction. The codons for the first 10 amino acids were optimized in the third position; the following 21 nucleotides are completely homologous for PCR priming. The 3' primer for

It has an XbάL site for cloning and 28 nucleotides of homologous sequence ending in the AccL site. The PCR product was 213 nucleotides.

The 5' primer for part B was: 5-AGTAGTCTAGAGTAGAOCAαX-ra-πα^ It has an Xbάl site for cloning and 22 nucleotides of homologous sequence starting from the Λccl site. The 3' primer for part B was: 5 AGATCOGCAGTTAa-KXriGAAGG CCnGlGT^^ It has a PstL site for cloning, a TAA stop codon and 27 nucleotides of homologous sequence. The PCR product was 591 nucleotides.

The expression vector was pJO201 which carries the ampicillin resistance gene and →kdsB, the gene which codes for CKS, driven by a modified lac promoter. CKS (CMP-KDO Synthetase) is an E. coli enzyme involved in cell wall biosynthesis. The enzyme has been overexpressed in E. coli using a modified lac promoter and has been used as a fusion partner to overexpress a number of genes (BioTechniquesNol.8, No. 5 [1990]). A multiple cloning site was engineered at the 3' end of kdsB; the cassettes were cloned as EcoRL/Pstl restriction fragments. Parts A and B were cloned in pJO201 (4.0 kilobases) to give plasmid pAlB6 of 4.8 kilobases. The plasmid was transformed in E. coli strain XLl-Blue to give strain SSHP1.

The strain was grown in L Broth to an OD600 of 0.5-1.0, induced with 1 mM IPTG and grown for an additional 4-16 hours. Expression of

CKS/HSV-2 protease was evaluated by SDS-PAGE; a band corresponding to the predicted molecular weight for HS V-2 protease fused to CKS (55 kilodaltons) was obtained as shown in Figure 3. The fusion protein was cleaved by digestion with factor Xa at an enzyme to substrate ratio of 1:200 (w/w) for 12 hours. Cleavage was evaluated by SDS-PAGE and Western Blots using an antibody against the CKS protein; production of bands corresponding to the predicted molecular weight for HSV-2 protease (26.6 kDa) and for CKS (28.8 kDa) were obtained.

Example 6

Production of an Antibody to HS V-2 Protease

Strain SSHP1 containing plasmid pAlB6 (prepared as desribed above) encoding CKS/HSV-2 protease( 1-247) was grown for expression as described in Example 5. Preparative SDS-PAGE was done on aliquots of whole cell lysates. Proteins were visualized with 0.25 M KCl/1 mM dithiothreitol and then destained with 1 mM dithiothreitol. The band corresponding to the predicted molecular weight for CKS/HSV-2 protease( 1-247), 55 kDa, was excised and used as the immunogen for antibody production. The protein was suspended in Freund complete adjuvant to approximately 0.1 mg/ml and was used to inject the animals. Two rabbits received initial injections and three boosts at approximately monthly intervals. Two weeks following the final boost, the animals were sacrificed and a large bleed was obtained as the source of antibody. The antibody was preabsorbed with E. coli XLl-Blue lysate for 48 hours and was used for Western Blots at a dilution of 1:1000.

Example 7 Construction of pA!B6C and Expression of HSV-2 Protease 1-307 as a CKS Fusion Protein

The cassette system described in Example 5 and Figure 2 was used to construct a CKS fusion to HSV-2 Protease (1-307). Part C was a new PCR product, parts A and B were identical to that described in Example 5. PCR conditions were as described in Example 5. The 5' primer for part C was: 5-lAGATCTAGAATOCXXXX-L\CACA<^^^ It contains an XbaL site for cloning, the AflLLL site and 26 nucleotides of homologous sequence. The 3' primer was:

It contains a PstL site for cloning, a TAA stop codon and 28 nucleotides of homologous sequence. The PCR product was 223 nucleotides.

Parts A, B and C were cloned in pJO201 to give the 5.0 kilobases plasmid pAlB6C3 which was transformed in E. coli strain XLl-Blue to give strain SSHP2. The strain was grown and evaluated for expression as described in Example 1. As shown in Figure 4, a band corresponding to the predicted molecular weight for the fusion protein (61 kilodaltons) was observed on SDS- PAGE. An additional band corresponding to the molecular weight of self- processed CKS/HS V-2 protease at amino acid 247 cleavage site (55kDa) was also observed.

Example 8 Construction of pA!B6Cmut and Expression of CKS/HSV-2 with 247 Mutation A mutation was made in HS V-2 Protease at amino acid position number

247 converting an alanine residue to a glycine residue at the protease clip site thereby eliminating self-processing at amino acid 247. The cassette system was as described in Example 5

Part Cmut was a new PCR product, parts A and B were identical to Example 1. The mutation was incorporated into the 5' PCR primer for part Cmut- The 5' primer for part Cmut was:

5"-TAGATCTAGAAT03∞GGA<-^ It contains an XbάL site for cloning, the AflLLL site, the Ala-Gly mutation and 33 nucleotides of homologous sequence. The 3' primer was identical to the 3' primer used for part C described in Example 7. PCR was conducted as described in Example 5 to give a 223 nucleotides PCR product.

Parts A, B and Cmut were cloned in pJO201 to give the 5.0 kilobases plasmid pAlB6C ut which was transformed in XLl-Blue to give strain SSHP3. The strain was grown and evaluated for expression as described in Example 5. A band corresponding to the predicted molecular weight for the fusion protein (61 kDa) was observed on SDS-PAGE as shown in Fgure 3. A 55 kDa band which would correspond to self-processed CKS/HSV-2 protease was not observed.

Example 9

Construction of pA2B6 and Expression of HSV-2 Proteasef 1-247)

Translationally Coupled to CKS

HSV-2 protease(l-247) was expressed translationally coupled to CKS.

A ribosome binding site was inserted between a 40 nucleotides 5' fragment of kdsB (described in Example 5) and the gene for HSV-2 protease in order to produce non-fused HS V-2 protease. The cassette system was as described in

Example 5; part A2 was a new PCR product, part B was identical to Example

5. The 5' primer for part A2 was:

5-TAGATGTOGAOΆAGGAGGTCATCΓAATGGCATCAGCAGAA^ TGAAOGTITAGAGGaj<-rTCIGOa-XiAaDCK-3-3^ It contains a SalL site for cloning, a consensus ribosome binding site and a TAA stop codon for CKS which overlaps with the ATG start site for HS V-2 protease. The codons for the first 10 amino acids of HSV-2 protease were optimized for E. coli in the third position; the following 21 nucleotides were completely homologous for PCR priming. The 3' primer was identical to the 3' primer for part A in Example 5. PCR was conducted as described in Example 5 to give a 216 nucleotides PCR product.

The expression vector was pJO201. A unique SalL site at 40 nucleotides downstream of the kdsB ATG start codon and the PstL site in the multi-cloning site were used to clone the PCR products. Translational coupling yielded a 19 aa product from kdsB and HSV-2 protease (1-247). Parts A2 and B were cloned in pJO201 to give plasmid pA2B6 of 4.1 kilobases. The plasmid was transformed in E. coli strain XLl-Blue to give strain SSHP4. The strain was grown and evaluated for expression as described in Example 5. A band corresponding to the predicted molecular weight of HS V-2 protease (27 kDa) was obtained on SDS-PAGE (Figure 4) and Western Blot (Figure 5).

Example 10 Construction of pA2B6C3 and Expression of HSV-2 Proteased -307) Translationally Coupled to CKS

HSV-2 protease(l-307) was expressed translationally coupled to CKS. The cassette system described in Example 5 and Figure 2 was used again in this example; part A2 was described in Example 9, parts B and C were described in Examples 5 and 7. Parts A2, B and C were cloned in pJO201to give the 4.3 kilobases plasmid pA2B6C3. The plasmid was transformed in E. coli strain XLl-Blue to give strain SSHP5. The strain was grown and evaluated for expression as described in Example 5. As shown in Figure 4, a band corresponding to the predicted molecular weight for HSV-2 protease(l- 307) was observed (33 kDa). In addition, a band corresponding to the molecular weight for self-processed HS V-2 protease (27 kDa) was also observed.

Example 11 Construction of pA2B6Cmut and Expression of HSV-2 Protease with Amino Acid 247 mutation

The mutation at the amino acid 247 protease self-processing site described in Example 8 was incorporated into the non-fused translationally coupled protease. The cassette system in Example 5 was again used: part A2 was as described in Example 9 part B described in Example 9 and part Cmut described in Example 8 were cloned in pJO201 to give the 4.3kb plasmid pA2B6Cmut. The plasmid was transformed in E. coli strain XLl-Blue to give strain SSHP6. The strain was grown and evaluated for expression as described in Example 5. As shown in Figure 3, a band corresponding to the predicted molecular weight for HSN-2 protease( 1-307) was observed (33 kDa). There was no band corresponding to the molecular weight for self-processed HSV-2 protease (27 kDa).

Example 12 Construction of pHPB-1

In this example a subclone was constructed of pH2ProB (prepared as described in Example 3) which contained only the 0.7 kilobases BamHL fragment encoding the remaining sequence of the assembly protein ICP35. The 0.7 kilobases -β HI fragment from pH2ProB was subcloned in pUC18. This construct was needed for subsequent construction of full length UL26 clones containing HSV-2 protease and ICP35.

Example 13 Construction of pSSPH-11 and Expression of HSV-2 Protease/ICP35 A CKS fusion was constructed to the entire UL26 encoding HS V-2 protease and ICP35 as outlined in Figure 6. Plasmid pAlB6C, described in Example 7, was digested with NcόL/PsiL and, in a triple ligation, was ligated to a 557 bp NcoL/SalL fragment of pH2ProA and a 81bp SalL/PstL fragment of pHPB-1, described in Example 12. The resulting intermediate clone pITL-6 was then digested with RsrLL/HinάLLL and ligated with a 610 bp RsrLL/HinάLLL fragment of pHPB-1 to give the final plasmid pSSPIl-11 of 5.9 kilobases. The plasmid was transformed in E. coli strain XLl-Blue to give strain SSHP7. The strain was grown and evaluated for expression as described in Example 5. A band corresponding to the predicted molecular weight for CKS/HS V-2 protease/ICP-35 fusion was observed (95 kDa).

Example 14 Construction of pALTHM-4 Containing His- 148 Mutation

The histidine residue at position 148 of HS V-2 protease was mutagenized to an alanine residue. The Altered Sites Mutagenesis Kit (supplied by Promega) was used following the manufacturer's protocols. A KpnL/SphL fragment of pSSPIl-11 was subcloned in the pALTER-1 mutagenesis vector provided in the kit. Mutagenesis at nucleotides 442-443 of HS V-2 protease was performed: CAC to GCC converting His- 148 to Ala and creating an EagL site for analysis of mutants. pALTHM-4 contained the desired mutation which was confirmed by DNA sequencing.

Example 15 Construction of pSSPI2 and Expression of HSV-2 Protease and ICP35 Translationally Coupled to CKS

In this example the UL26 gene encoding HS V-2 Protease and ICP35 was translationally coupled to CKS. The plasmid pA2B6C was the parent vector for this construct. A 1441bp NcoL/HinάLLL fragment from pSSPIl-11 containing the 3' portion of HSV-2 Protease and the ICP35 gene was cloned in pA2B6C to give the 5.2 kilobases plasmid pSSPI2. The plasmid was transformed in E. coli strain XLl-Blue to give strain SSHP8. The strain was grown and evaluated for expression as described in Example 5. As shown in Figure 7, a band corresponding to the predicted molecular weight for HSV-2 protease/ICP-35 fusion was observed (67 kDa) along with the 27 kDa self processed protein corresponding to the molecular weight for HS V-2 Protease (1-247).

Example \6 Construction of pSSPI2M and Expression of Mutant HS V-2 Protease and ICP35 Translationally Coupled to CKS

The UL26 gene encoding HS V-2 protease with the amino acid 247 deletion, described in Example 8, and ICP35 was translationally coupled to CKS. The plasmid pA2B6Cmut was the parent vector for this construct. A 1441 bp NcoL/HinάLLL fragment from pSSPIl-11 containing the 3' portion of HSV-2 protease and the ICP35 gene was cloned in pA2B6Cmut to give plasmid pSSPI2M. The plasmid was transformed in E. coli strain XLl-Blue to give strain SSHP9. The strain was grown and evaluated for expression as described in Example 5. A band corresponding to the predicted molecular weight for HSV-2 protease/ICP-35 was observed (67 kDa) as shown in Figure 7. There was no evidence of the 27 kDa self processed protein corresponding to the molecular weight for HSV-2 protease (1-247) on SDS-PAGE or Western blots. gxatnplg 17 Expression of Uι_26 in S. cerevisiae

The plasmid pSSPIl-11, prepared as described in Example 13, was digested with EcoRI and the sticky ends were blunt ended by large fragment of DNA polymerase according to manufacturer's instructions. The DNA was then digested with Xbal and electrophoresed on 1% low melt agarose gel. A 2.3 kilobases fragment containing the UL26 gene was excised from the gel and then ligated to pVTIOO-U at the Pvul l/Xbal sites. The ligation mix was transformed into E. coli DH5α. The plasmid pVTIOO-U UL26, containing the UL26 gene was identified by digestion with Hindi 11/ Xbal which released a 2.3 kilobases fragment.

Yeast strain YJO was transformed with pVTIOO-U or pVTIOO-U UL26 employing selection for uracil prototrophy. Transformants were grown at 30 °C in liquid media lacking uracil and containing 2% glucose and examined for expression as described in Example 5. An immunoreactive band of 27 kDa was detected (Figure 8, lanes 5, 6) indicating that the UL26 gene product (HS V-2 protease) is active in S. cerevisiae.

Example 18

Expression of Wild-type and Mutant HSV-2 Protease in the Baculovirus System and Demonstration of In Vivo Activity

In order to obtain high levels of HSV-2 protease expression, the gene was cloned into the transfer vector pVL1392, placing it under the control of the strong Polyhedrin promoter of the Baculovirus, Autographa californica

Nuclear Polyhedrosis Virus. The gene was then integrated into the linearized Baculogold virus in the insect cell host by homologous recombination. Recombinant viruses were then used to infect insect cells in tissue culture to produce the protease. A DNA fragment coding for the HSV-2 protease UL26 gene was excised from plasmid pSSPIl-11 (described in Example 13) in the following manner: the plasmid was first digested with Xba I, then treated with the Klenow fragment of DNA Polymerase to generate a blunt end, followed by digestion with Eco Rl. A resulting DNA fragment of approximately 2 kilobases was purified through an agarose gel and ligated to the transfer vector pVL1392 which was previously digested with Eco Rl and SmάL, to create the plasmid pAcUL26. Similarly, the plasmid pALTHM-4 (described in Example 13) containing the HSV-2 U 26 gene with a mutation at the active site His- 148 was digested with Hwdiπ, made blunt with Klenow polymerase, cut with Eco Rl, and the 2 kilobases DNA fragment generated was gel purified and ligated to Eco Rl and Sma I cut pVL1392, to generate the plasmid pAcΗ148.

Recombinant viruses were derived by co-transfection of 5 μg of either pAcUL26 or pAcH148 with 0.5 μg of linearized Baculogold DNA using the reagents for calcium phosphate precipitation supplied in the kit. The Baculogold DNA contains a lethal deletion of ORFl 629 and is not viable unless rescued by recombination with the transfer vector containing ORFl 629 and the gene to be expressed, thus providing a selection for recombinant virus. After transfection, the Sf9 cells were incubated in 4 ml TMN-FH media for 5 days and monitored for signs of infection, ie, enlargement of cells, loss of cell viability, or lysis. Supernatants were harvested, cells were removed by low speed centrifugation, and 1 ml of this low titre viral stock was used to infect a new flask containing 2 x 10^ Sf9 cells. Once more, cells were incubated for 3 to 5 days until signs of infection were apparent, thus indicating production of a high titre virus stock.

To assay for expression of either UL26 or the His- 148 mutant gene, fresh Sf9 cells were infected with the high titre stocks of VACUL26 or vAcH148 generated as described above and soluble extracts were prepared. Figure 9 shows the results of SDS-PAGE analysis of 20 μl aliqouts of soluble extracts of uninfected cells (lane 3), wild-type Baculovirus infected lysate (lane 4), VACUL26 infected lysate (lane5), and vAcH148 infected lysate (lane 6), after staining with Coomasie blue. As expected, the polyprotein from the UL26 gene made in vAcUL26-infected cells undergoes autoproteolysis to produce the 27 kDa protease and the 40 kDa ICP-35 protein, indicating that the HS V-2 protease is active in these cells. In vAcH148 infected cells, the mutation in the active site of the protease greatly reduces autoproteolysis and the 67 kd polyprotein is the predominant form observed. This shows that processing of the polyprotein is not due to an endogenous protease of viral or cellular origin but an intrinsic function of the active HS V-2 protease, itself. The Western blot, shown in Figure 10 confirms that the proteins produced in virus infected cells are the pro- and mature forms of HSV-2 protease. Example 19 Preparation of antibody to the 236-247 region of HSV-2 protease

A peptide of the sequence Gln-Ala-Gly-Ile-Ala-Gly-His-Thr-Tyr-Leu- Gln-Ala was synthesized commercially using standard techniques. This sequence corresponds to the residues 236-247 of the UL26 gene product and the carboxy terminal 12 amino acids of the mature form of HSV-2 protease. The peptide was conjugated to keyhole limpet hemocyanin using a commercially available kit (Pierce). The conjugated peptide was then emulsified with Freund's adjuvant and injected into several subcutaneous dorsal sites of New Zealand white rabbits (approx. 0.5 mg peptide per immunization). Immunization boosts were also administered two and six weeks later. The animals were bled prior to primary immunization and also at four, eight and ten weeks after primary immunization. The serum was collected from clotted blood by centrifugation, heated to 56°C for 30 minutes, and then stored at -20 °C.

Example 20 Expression of the Uτ_26 gene in insect larvae using a recombinant baculovirus vector, Cabbage looper larvae were grown on the semisynthetic diet at 27 °C and 50% relative humidity until the fourth instar stage. Shortly after molting, the insects were removed from their diets, housed individually in plastic Petri dishes, and starved for 18 hours. The insects were then placed into contact with 10 μl of insect cell culture fluid (see Example 18) which was infected with either 1) wild-type nuclear polyhedrosis virus (Autograp→ha californica ), 2) recombinant baculovirus with the UL26 gene for HS V-2 ( VACUL26), 3) recombinant baculovirus and wild type nuclear polyhedrosis virus in a 10:1 ratio, or 4) no baculovirus. Each of the cell culture fluids contained 10% sucrose to stimulate drinking. The larvae were observed until they drank part of their culture fluid, and then they were left in contact with their respective culture fluid for an additional three hours. After this period they were placed onto the surface of fresh semisynthetic diet (< 6 larvae/cup) and maintained at 28 °C and 70% relative humidity. On days 3-5 postinfection, dead and moribund larvae were collected and frozen at -70 °C. Frozen larvae were thawed and placed into extraction buffer (50 mM Kphosphate, pH 7.5, 150 mM NaCl, 1 mM EDTA, 0.4 mM β-mercaptoethanol, 0.5% Triton X-100, and 10% glycerol) in a 10 μl buffer/mg larvae proportion. The larval suspensions were homogenized using a mortar and pestle. Aliquots were removed and centrifuged in a microfuge for 3 minutes at high speed. Aliquots from the supernatent fractions were denatured and electrophoresed on 12.5% SDS-polyacrylamide gels. The gels were either stained for protein using Coomasie Brilliant Blue R-250 or electrophoretically transferred to PVDF membranes for Western Blot analysis. The primary antibody solutions were prepared in TBST buffer containing 0.75% bovine serum albumin and an antibody derived either from the 236-247 HS V-2 protease peptide (Example 19) or the CKS-HSV-2 protease fusion protein (from Example 6).

The Coomasie stained gel, shown in Figure 11, shows the presence of a 27 kDa band not present in larvae infected with only wild-type baculovirus or with no virus . These data suggest that the recombinant VACUL26 baculovirus infected larvae expressed a protein of about 27 kDa. The Western blot analysis (Figure 12) confirms this interpretation, showing that the primary antibody to the 236-247 peptide fragment of HSV-2 protease reacts positively only with the 27 kDa band in VACUL26 treated larvae and some minor degradation products. These results show that the UL26 protein produced in Tric→hoplusia ni is active and capable of self-processing to the mature 27 kDa form. It will be appreciated by those skilled in the art that the specific embodiments of the present invention can be modified or changed without departing from the scope or spirit of the invention. For example, due to codon degeneracy, changes can be made in the underlying DNA sequence without affecting the protein sequence. Moreover, due to biological functional equivalency considerations, changes can be made in the protein structure and still achieve a useful protease. All such modifications are intended to be included within the scope of the appended claims. SEQUENCE LISTING

(1) GENERAL INFORMATION:

(i) APPLICANT: STEFFY, K. et al (ii) TITLE OF INVENTION: HERPES SIMPLEX VIRUS TYPE 2 PROTEASE (iii) NUMBER OF SEQUENCES: 12

(iv) CORRESPONDENCE ADDRESS:

(A) ADDRESSEE: ABBOTT LABORATORIES

(B) STREET: ONE ABBOTT PARK ROAD

(C) CITY: ABBOTT PARK

(D) STATE: IL

(E) COUNTRY: USA

(F) ZIP: 60064

(v) COMPUTER READABLE FORM:

(A) MEDIUM TYPE: Floppy disk

(B) COMPUTER: IBM PC compatible

(C) OPERATING SYSTEM: PC-DOS/MS-DOS

(D) SOFTWARE: Patentin Release #1.0, Version #1.25

(vi) CURRENT APPLICATION DATA:

(A) APPLICATION NUMBER:

(B) FILING DATE:

(C) CLASSIFICATION:

(vii) PRIOR APPLICATION DATA:

(A) APPLICATION NUMBER: US 08/073,819

(B) FILING DATE: 06-JUN-1993

(viii) ATTORNEY/AGENT INFORMATION:

(A) NAME: cro ley, s.

(B) REGISTRATION NUMBER: 31604

(C) REFERENCE/DOCKET NUMBER: 5363.US.Pl

(ix) TELECOMMUNICATION INFORMATION: (A) TELEPHONE: 708-938-7742

(2) INFORMATION FOR SEQ ID Nθ:l:

(i) SEQUENCE CHARACTERISTICS:

(A) LENGTH: 2151 base pairs

(B) TYPE: nucleic acid

(C) STRANDEDNESS: single

(D) TOPOLOGY: linear

(ii) MOLECULE TYPE: DNA (genomic) (iii) HYPOTHETICAL: NO

(v) FRAGMENT TYPE: internal (vi) ORIGINAL SOURCE:

(A) ORGANISM: HSV 2

(ix) FEATURE:

(A) NAME/KEY: CDS

(B) LOCATION: 211..951

(D) OTHER INFORMATION: /product= "HSV2 PROTEASE"

(ix) FEATURE:

(A) NAME/KEY: CDS

(B) LOCATION: 1126..2151

(D) OTHER INFORMATION: /product= "ICP35 PROTEIN"

(xi) SEQUENCE DESCRIPTION: SEQ ID NO:l:

GTTTTTCTGT TGTTGTTTCT GGTCCGCCTG GTCACTAAAA GGCACGCCCC TTACATACTG 60

CGGGCTTTAG TCCCGGTCCC GGACTGTCGG CTGGACACAC AACAACGGCT GGGCCCGTGG 120

GTGGGTAAGT TGGTTCGGGG GCACTGCTGT TATTCCCTTG CCCGCTTCCA CCCCCCCCCC 180

TTCCCGTTTT GTTTGTTTGT GCGGGTGCCC ATG GCG TCG GCG GAA ATG CGC GAG 234

Met Ala Ser Ala Glu Met Arg Glu 1 5

CGG TTG GAG GCG CCT CTG CCC GAC CGG GCG GTG CCC ATC TAC GTG GCC 282 Arg Leu Glu Ala Pro Leu Pro Asp Arg Ala Val Pro lie Tyr Val Ala 10 15 20

GGG TTT TTG GCC CTG TAC GAC AGC GGG GAC TCC GGC GAG CTG GCC CTG 330 Gly Phe Leu Ala Leu Tyr Asp Ser Gly Asp Ser Gly Glu Leu Ala Leu 25 30 35 40

GAC CCA GAC ACG GTG CGT GCG GCC CTG CCT CCG GAG AAC CCC CTG CCG 378 Asp Pro Asp Thr Val Arg Ala Ala Leu Pro Pro Glu Asn Pro Leu Pro 45 50 55

ATC AAC GTA GAC CAC CGC GCT CGG TGC GAG GTG GGC CGG GTG CTC GCC 426 lie Asn Val Asp His Arg Ala Arg Cys Glu Val Gly Arg Val Leu Ala 60 65 70

GTG GTC AAC GAC CCT CGG GGG CCG TTT TTT GTG GGG CTG ATC GCG TGC 474 Val Val Asn Asp Pro Arg Gly Pro Phe Phe Val Gly Leu lie Ala Cys 75 80 85

GTG CAG CTG GAG CGC GTC CTC GAG ACG GCC GCC AGC GCC GCT ATT TTT 522 Val Gin Leu Glu Arg Val Leu Glu Thr Ala Ala Ser Ala Ala lie Phe 90 95 100

GAG CGC CGC GGA CCC GCG CTC TCC CGG GAG GAG CGT CTG CTG TAC CTG 570 Glu Arg Arg Gly Pro Ala Leu Ser Arg Glu Glu Arg Leu Leu Tyr Leu 105 110 115 120 ATC ACC AAC TAC CTG CCA TCG GTC TCG CTG TCC ACA AAA CGC CGG GGG 618 lie Thr Asn Tyr Leu Pro Ser Val Ser Leu Ser Thr Lys Arg Arg Gly 125 130 135

GAC GAG GTT CCG CCC GAC CCC ACC CTG TTT GCG CAC GTG GCC CTG TGC 666 Asp Glu Val Pro Pro Asp Pro Thr Leu Phe Ala His Val Ala Leu Cys 140 145 150

GCC ATC GGG CGT CGC CTT GGA ACC ATC GTC ACC TAC GAC ACC AGC CTA 714 Ala lie Gly Arg Arg Leu Gly Thr lie Val Thr Tyr Asp Thr Ser Leu 155 160 165

GAC GCG GCC ATC GCT CCG TTT CGC CAC CTG GAC CCG GCG ACG CGC GAG 762 Asp Ala Ala lie Ala Pro Phe Arg His Leu Asp Pro Ala Thr Arg Glu 170 175 180

GGG GTG CGA CGC GAG GCC GCC GAG GCC GAG CTC GCG CTG GCC GGG CGC 810 Gly Val Arg Arg Glu Ala Ala Glu Ala Glu Leu Ala Leu Ala Gly Arg 185 190 195 200

ACC TGG GCC CCC GGC GTG GAG GCG CTC ACA CAC ACG CTG CTC TCC ACC 858 Thr Trp Ala Pro Gly Val Glu Ala Leu Thr His Thr Leu Leu Ser Thr 205 210 215

GCC GTC AAC AAC ATG ATG CTG CGT GAC CGC TGG AGC CTC GTG GCC GAG 906 Ala Val Asn Asn Met Met Leu Arg Asp Arg Trp Ser Leu Val Ala Glu 220 225 230

CGG CGG CGG CAG GCC GGG ATC GCC GGA CAC ACG TAC CTT CAG GCG 951 Arg Arg Arg Gin Ala Gly lie Ala Gly His Thr Tyr Leu Gin Ala 235 240 245

AGCGAAAAAT TTAAAATATG GGGGGCGGAG TCTGCCCCTG CGCCGGAGCG CGGGTATAAA 1011

ACCGGCGCCC CGGGTGCCAT GGACACATCC CCCGCCGCGA GCGTTCCCGC GCCGCAGGTC 1071

GCCGTCCGTG CGCGTCAAGT CGCGTCGTCG TCGTCTTCTT CTTTTCCGGC ACCG GCC 1128

Ala 1

GAT ATG AAC CCC GTT TCG GCA TCG GGC GCC CCG GCC CCT CCG CCG CCC 1176 Asp Met Asn Pro Val Ser Ala Ser Gly Ala Pro Ala Pro Pro Pro Pro 5 10 15

GGC GAC GGG AGT TAT TTG TGG ATC CCC GCC TCT CAT TAC AAT CAG CTC 1224 Gly Asp Gly Ser Tyr Leu Trp lie Pro Ala Ser His Tyr Asn Gin Leu 20 25 30

GTC ACC GGG CAA TCC GCG CCC CGC CAC CCG CCG CTG ACC GCG TGC GGC 1272 Val Thr Gly Gin Ser Ala Pro Arg His Pro Pro Leu Thr Ala Cys Gly 35 40 45

CTG CCG GCC GCG GGG ACG GTG GCC TAC GGA CAC CCC GGC GCC GGC CCG 1320 Leu Pro Ala Ala Gly Thr Val Ala Tyr Gly His Pro Gly Ala Gly Pro 50 55 60 65 TCC CCG CAC TAC CCG CCT CCT CCC GCC CAC CCG TAC CCG GGT ATG CTG 1368 Ser Pro His Tyr Pro Pro Pro Pro Ala His Pro Tyr Pro Gly Met Leu 70 75 80

TTC GCG GGC CCC AGT CCC CTG GAG GCC CAG ATC GCC GCG CTG GTG GGG 1416 Phe Ala Gly Pro Ser Pro Leu Glu Ala Gin lie Ala Ala Leu Val Gly 85 90 95

GCC ATC GCC GCC GAC CGC CAG GCG GGT GGG CTT CCG GCG GCC GCC GGA 1464 Ala lie Ala Ala Asp Arg Gin Ala Gly Gly Leu Pro Ala Ala Ala Gly 100 105 110

GAC CAC GGG ATC CGG GGG TCG GCG AAG CGC CGC CGA CAC GAG GTG GAG 1512 Asp His Gly lie Arg Gly Ser Ala Lys Arg Arg Arg His Glu Val Glu 115 120 125

CAG CCG GAG TAC GAC TGC GGC CGT GAC GAG CCG GAC CGG GAC TTC CCG 1560 Gin Pro Glu Tyr Asp Cys Gly Arg Asp Glu Pro Asp Arg Asp Phe Pro 130 135 140 145

TAT TAC CCG GGC GAG GCC CGC CCC GAG CCG CGC CCG GTC GAC TCC CGG 1608 Tyr Tyr Pro Gly Glu Ala Arg Pro Glu Pro Arg Pro Val Asp Ser Arg 150 155 160

CGC GCC GCG CGC CAG GCT TCC GGG CCC CAC GAA ACC ATC ACG GCG CTG 1656 Arg Ala Ala Arg Gin Ala Ser Gly Pro His Glu Thr lie Thr Ala Leu 165 170 175

GTG GGG GCG GTG ACG TCC CTG CAG CAG GAA CTG GCG CAC ATG CGC GCG 1704 Val Gly Ala Val Thr Ser Leu Gin Gin Glu Leu Ala His Met Arg Ala 180 185 190

CGT ACC CAC GCC CCC TAC GGG CCG TAT CCG CCG GTG GGG CCC TAC CAC 1752 Arg Thr His Ala Pro Tyr Gly Pro Tyr Pro Pro Val Gly Pro Tyr His 195 200 205

CAC CCC CAC GCA GAC ACG GAG ACC CCC GCC CAA CCA CCC CGC TAC CCC 1800 His Pro His Ala Asp Thr Glu Thr Pro Ala Gin Pro Pro Arg Tyr Pro 210 215 220 225

GCC GAG GCC GTC TAT CTG CCG CCG CCG CAC ATC GCC CCC CCG GGG CCT 1848 Ala Glu Ala Val Tyr Leu Pro Pro Pro His lie Ala Pro Pro Gly Pro 230 235 240

CCT CTA TCC GGG GCG GTC CCC CCA CCC TCG TAT CCC CCC GTT GCG GTT 1896 Pro Leu Ser Gly Ala Val Pro Pro Pro Ser Tyr Pro Pro Val Ala Val 245 250 255

ACC CCC GGT CCC GCT CCC CCG CTA CAT CAG CCC TCC CCC GCA CAC GCC 1944 Thr Pro Gly Pro Ala Pro Pro Leu His Gin Pro Ser Pro Ala His Ala 260 265 270

CAC CCC CCT CCG CCG CCG CCG GGA CCC ACG CCT CCC CCC GCC GCG AGC 1992 His Pro Pro Pro Pro Pro Pro Gly Pro Thr Pro Pro Pro Ala Ala Ser 275 280 285 TTA CCC CAA CCC GAG GCG CCC GGC GCG GAG GCC GGC GCC TTA GTT AAC 2040 Leu Pro Gin Pro Glu Ala Pro Gly Ala Glu Ala Gly Ala Leu Val Asn 290 295 300 305

GCC AGC AGC GCG GCC CAC GTG AAC GTG GAC ACG GCC CGG GCC GCC GAT 2088 Ala Ser Ser Ala Ala His Val Asn Val Asp Thr Ala Arg Ala Ala Asp 310 315 320

CTG TTT GTG TCA CAG ATG ATG GGG TCC CGC TGA TGG GGT CCC GCT AAC 2136 Leu Phe Val Ser Gin Met Met Gly Ser Arg * Trp Gly Pro Ala Asn 325 330 335

TCG CCT CCA GGA TCC 2151

Ser Pro Pro Gly Ser 340

(2) INFORMATION FOR SEQ ID NO:2:

(i) SEQUENCE CHARACTERISTICS:

(A) LENGTH: 247 amino acids

(B) TYPE: amino acid (D) TOPOLOGY: linear

(ii) MOLECULE TYPE: protein

(xi) SEQUENCE DESCRIPTION: SEQ ID NO:2:

Met Ala Ser Ala Glu Met Arg Glu Arg Leu Glu Ala Pro Leu Pro Asp 1 5 10 15

Arg Ala Val Pro lie Tyr Val Ala Gly Phe Leu Ala Leu Tyr Asp Ser 20 25 30

Gly Asp Ser Gly Glu Leu Ala Leu Asp Pro Asp Thr Val Arg Ala Ala 35 40 45

Leu Pro Pro Glu Asn Pro Leu Pro lie Asn Val Asp His Arg Ala Arg 50 55 60

Cys Glu Val Gly Arg Val Leu Ala Val Val Asn Asp Pro Arg Gly Pro 65 70 75 80

Phe Phe Val Gly Leu lie Ala Cys Val Gin Leu Glu Arg Val Leu Glu 85 90 95

Thr Ala Ala Ser Ala Ala lie Phe Glu Arg Arg Gly Pro Ala Leu Ser 100 105 110

Arg Glu Glu Arg Leu Leu Tyr Leu lie Thr Asn Tyr Leu Pro Ser Val 115 120 125

Ser Leu Ser Thr Lys Arg Arg Gly Asp Glu Val Pro Pro Asp Pro Thr 130 135 140

Leu Phe Ala His Val Ala Leu Cys Ala lie Gly Arg Arg Leu Gly Thr 145 150 155 160 lie Val Thr Tyr Asp Thr Ser Leu Asp Ala Ala lie Ala Pro Phe Arg 165 170 175

His Leu Asp Pro Ala Thr Arg Glu Gly Val Arg Arg Glu Ala Ala Glu 180 185 190

Ala Glu Leu Ala Leu Ala Gly Arg Thr Trp Ala Pro Gly Val Glu Ala 195 200 205

Leu Thr His Thr Leu Leu Ser Thr Ala Val Asn Asn Met Met Leu Arg 210 215 220

Asp Arg Trp Ser Leu Val Ala Glu Arg Arg Arg Gin Ala Gly lie Ala 225 230 235 240

Gly His Thr Tyr Leu Gin Ala 245

(2) INFORMATION FOR SEQ ID NO:3:

(i) SEQUENCE CHARACTERISTICS:

(A) LENGTH: 342 amino acids

(B) TYPE: amino acid (D) TOPOLOGY: linear

(ii) MOLECULE TYPE: protein

(xi) SEQUENCE DESCRIPTION: SEQ ID NO:3:

Ala Asp Met Asn Pro Val Ser Ala Ser Gly Ala Pro Ala Pro Pro Pro 1 5 10 15

Pro Gly Asp Gly Ser Tyr Leu Trp lie Pro Ala Ser His Tyr Asn Gin 20 25 30

Leu Val Thr Gly Gin Ser Ala Pro Arg His Pro Pro Leu Thr Ala Cys 35 40 45

Gly Leu Pro Ala Ala Gly Thr Val Ala Tyr Gly His Pro Gly Ala Gly 50 55 60

Pro Ser Pro His Tyr Pro Pro Pro Pro Ala His Pro Tyr Pro Gly Met 65 70 75 80

Leu Phe Ala Gly Pro Ser Pro Leu Glu Ala Gin lie Ala Ala Leu Val 85 90 95

Gly Ala lie Ala Ala Asp Arg Gin Ala Gly Gly Leu Pro Ala Ala Ala 100 105 110

Gly Asp His Gly lie Arg Gly Ser Ala Lys Arg Arg Arg His Glu Val 115 120 125

Glu Gin Pro Glu Tyr Asp Cys Gly Arg Asp Glu Pro Asp Arg Asp Phe 130 135 140 Pro Tyr Tyr Pro Gly Glu Ala Arg Pro Glu Pro Arg Pro Val Asp Ser 145 150 155 160

Arg Arg Ala Ala Arg Gin Ala Ser Gly Pro His Glu Thr lie Thr Ala 165 170 175

Leu Val Gly Ala Val Thr Ser Leu Gin Gin Glu Leu Ala His Met Arg 180 185 190

Ala Arg Thr His Ala Pro Tyr Gly Pro Tyr Pro Pro Val Gly Pro Tyr 195 200 205

His His Pro His Ala Asp Thr Glu Thr Pro Ala Gin Pro Pro Arg Tyr 210 215 220

Pro Ala Glu Ala Val Tyr Leu Pro Pro Pro His lie Ala Pro Pro Gly 225 230 235 240

Pro Pro Leu Ser Gly Ala Val Pro Pro Pro Ser Tyr Pro Pro Val Ala 245 x 250 255

Val Thr Pro Gly Pro Ala Pro Pro Leu His Gin Pro Ser Pro Ala His 260 265 270

Ala His Pro Pro Pro Pro Pro Pro Gly Pro Thr Pro Pro Pro Ala Ala 275 280 285

Ser Leu Pro Gin Pro Glu Ala Pro Gly Ala Glu Ala Gly Ala Leu Val 290 295 300

Asn Ala Ser Ser Ala Ala His Val Asn Val Asp Thr Ala Arg Ala Ala 305 310 315 320

Asp Leu Phe Val Ser Gin Met Met Gly Ser Arg * Trp Gly Pro Ala 325 330 335

Asn Ser Pro Pro Gly Ser 340

(2) INFORMATION FOR SEQ ID NO:4:

(i) SEQUENCE CHARACTERISTICS:

(A) LENGTH: 74 base pairs

(B) TYPE: nucleic acid

(C) STRANDEDNESS: single

(D) TOPOLOGY: linear

(ii) MOLECULE TYPE: cDNA

(iii) HYPOTHETICAL: NO

(vi) ORIGINAL SOURCE:

(B) STRAIN: SYNTHETIC

(xi) SEQUENCE DESCRIPTION: SEQ ID NO:4: TAGATGAATT CATAGAAGGT CGTATGGCAT CAGCAGAAAT GCGTGAACGT TTAGAGGCGC 60 CTCTGCCCGA CCGG 74

(2) INFORMATION FOR SEQ ID NO:5:

(i) SEQUENCE CHARACTERISTICS:

(A) LENGTH: 41 base pairs

(B) TYPE: nucleic acid

(C) STRANDEDNESS: single

(D) TOPOLOGY: linear

(ii) MOLECULE TYPE: cDNA

(iii) HYPOTHETICAL: NO

(vi) ORIGINAL SOURCE:

(B) STRAIN: SYNTHETIC

(xi) SEQUENCE DESCRIPTION: SEQ ID NO:5: AGTAGTCTAG AGTCTACGTT GATCGGCAGG GGGTTCTCCG G 41

(2) INFORMATION FOR SEQ ID NO:6:

(i) SEQUENCE CHARACTERISTICS:

(A) LENGTH: 38 base pairs

(B) TYPE: nucleic acid

(C) STRANDEDNESS: single

(D) TOPOLOGY: linear

(ii) MOLECULE TYPE: cDNA

(iii) HYPOTHETICAL: NO

(vi) ORIGINAL SOURCE:

(B) STRAIN: SYNTHETIC

(xi) SEQUENCE DESCRIPTION: SEQ ID NO:6: AGTAGTCTAG ATAGACCACC GCGCTGGGTG CGAGGTGG 38

(2) INFORMATION FOR SEQ ID NO:7:

(i) SEQUENCE CHARACTERISTICS:

(A) LENGTH: 41 base pairs

(B) TYPE: nucleic acid

(C) STRANDEDNESS: single

(D) TOPOLOGY: linear

(ii) MOLECULE TYPE: cDNA (iii) HYPOTHETICAL: NO (vi) ORIGINAL SOURCE:

(B) STRAIN: SYNTHETIC

(xi) SEQUENCE DESCRIPTION: SEQ ID NO:7: AGATGCTGCA GTTACGCCTG AAGGTACGTG TGTCCGGCGA T 41

(2) INFORMATION FOR SEQ ID NO:8:

(i) SEQUENCE CHARACTERISTICS:

(A) LENGTH: 36 base pairs

(B) TYPE: nucleic acid

(C) STRANDEDNESS: single

(D) TOPOLOGY: linear

(ii) MOLECULE TYPE: cDNA

(iii) HYPOTHETICAL: NO

(vi) ORIGINAL SOURCE:

(B) STRAIN: SYNTHETIC

(xi) SEQUENCE DESCRIPTION: SEQ ID NO:8: TAGATCTAGA ATCGCCGGAC ACACGTACCT TCAGGC 36

(2) INFORMATION FOR SEQ ID NO:9:

(i) SEQUENCE CHARACTERISTICS:

(A) LENGTH: 36 base pairs

(B) TYPE: nucleic acid

(C) STRANDEDNESS: single

(D) TOPOLOGY: linear

(ii) MOLECULE TYPE: cDNA

(iii) HYPOTHETICAL: NO

(vi) ORIGINAL SOURCE:

(B) STRAIN: SYNTHETIC

(xi) SEQUENCE DESCRIPTION: SEQ ID NO:9: TAGATCTAGA ATCGCCGGAC ACACGTACCT TCAGGC 36

(2) INFORMATION FOR SEQ ID NO:10:

(i) SEQUENCE CHARACTERISTICS:

(A) LENGTH: 34 base pairs

(B) TYPE: nucleic acid

(C) STRANDEDNESS: single

(D) TOPOLOGY: linear

(ii) MOLECULE TYPE: cDNA (iii) HYPOTHETICAL: NO

(vi) ORIGINAL SOURCE:

(B) STRAIN: SYNTHETIC

(xi) SEQUENCE DESCRIPTION: SEQ ID NO:10: GAACTGCAGT TAATCGGCCG GTGCCGGAAA AGAA 34

(2) INFORMATION FOR SEQ ID NO:11:

(i) SEQUENCE CHARACTERISTICS:

(A) LENGTH: 44 base pairs

(B) TYPE: nucleic acid

(C) STRANDEDNESS: single

(D) TOPOLOGY: linear

(ii) MOLECULE TYPE: cDNA

(iii) HYPOTHETICAL: NO

(vi) ORIGINAL SOURCE:

(B) STRAIN: SYNTHETIC

(xi) SEQUENCE DESCRIPTION: SEQ ID NO:11: TAGATCTAGA ATCGCCGGAC ACACGTACCT TCAGGGGAGC GAAA 44

(2) INFORMATION FOR SEQ ID NO:12:

(i) SEQUENCE CHARACTERISTICS:

(A) LENGTH: 78 base pairs

(B) TYPE: nucleic acid

(C) STRANDEDNESS: single

(D) TOPOLOGY: linear

(ii) MOLECULE TYPE: cDNA

(iii) HYPOTHETICAL: NO

(vi) ORIGINAL SOURCE:

(B) STRAIN: SYNTHETIC

(xi) SEQUENCE DESCRIPTION: SEQ ID NO:12: TAGAGTTCGA CTTAAGGAAG GTGATCTAAT GGCATCAGCA GAATGCGTGA ACGTTTAGAG 60 GCGCCTCTGC CCGACCGG 78

Claims

What is claimed is:

1. A herpes protease from Herpes Simplex Virus Type 2.

2. The herpes protease of claim 1 further characterized as having the ability to cleave a herpes virus assembly protein precursor.

3. The herpes protease of claim 1 further characterized as having the ability to cleave a herpes virus assembly protein precursor of Herpes Simplex Virus Type 2.

4. A herpes protease of claim 1 further identified as comprising an amino acid sequence of Figure 1.

5. An amino acid sequence which is at least approximately seventy percent homologous to the amino acid sequence of Figure 1.

6. An amino acid sequence which is at least approximately ninety percent homologous to the amino acid sequence of Figure 1.

7. An isolated nucleic acid sequence which encodes a herpes simplex virus type 2 protease or portion thereof.

8. The nucleic acid sequence of claim 7 which encodes a protease having the ability to cleave a herpes virus assembly protein precursor.

9. The nucleic acid sequence of claim 7 which encodes a protease having the ability to cleave a herpes virus assembly protein precursor of Herpes Simplex Virus Type 2.

10. A nucleic acid sequence encoding a herpes protease as shown in Figure 1.

11. A nucleic acid segment comprising a nucleic acid sequence which is at least approximately seventy percent homologous to the nucleic acid sequence of Figure 1.

12. A nucleic acid segment comprising a nucleic acid sequence which is at least approximately ninety percent homologous to the nucleic acid sequence of Figure 1.

13. A recombinant vector comprising a nucleic acid sequence encoding a herpes simplex virus type 2 protease or portion thereof.

14. The vector of claim 13 further identified as an expression vector.

15. The vector of claim 14 further identified as comprising a promoter.

16. A recombinant host cell transformed with a recombinant vector comprising a nucleic acid sequence encoding a herpes simplex virus type 2 protease or portion thereof.

17. The recombinant host cell of claim 16 wherein the host is selected from a bacteria, yeast or insect cell.

18. The host cell of claim 17 wherein the host is E. coli, Saccharomyces cerevisiae, or Trichoplusia i.