CA2216755A1

CA2216755A1 - Peptides with growth promotion properties

Info

Publication number: CA2216755A1
Application number: CA002216755A
Authority: CA
Inventors: Brian Lee Buckwalter; Hong-Ming Shieh; Bosco Shang Wang
Original assignee: Individual
Current assignee: Wyeth Holdings LLC
Priority date: 1995-03-31
Filing date: 1996-03-15
Publication date: 1996-10-03
Also published as: PL322585A1; JPH11502844A; KR19980703438A; WO1996030405A1; MX9707433A; EP0819137A1; AU5422596A; HUP9801337A2; BG101927A

Abstract

Peptides are described which have well-defined secondary structure, preferably a helical conformation, which mimic the corresponding region of porcine somatotropin (pST) and which enhance the activity of pST and promote growth of warm-blooded animals. These peptides compete with pST for binding to the PS-7.6 monoclonal antibody. These peptides contain therein the sequence of amino acids Xaa-Xaa-Leu-Xaa-Xaa-Ile-Xaa-Xaa-Xaa-Leu-Xaa-Xaa-Val-Xaa-Xaa (SEQ ID No.
1), wherein the sequence differs from the native sequence of pST, as well as sequences in which the location of essential amino acids is shifted by three amino acids, representing almost one turn along the helix, which contain therein the sequence of amino acids Xaa-Xaa-Xaa-Xaa-Xaa-Leu-Xaa-Xaa-Xaa-Ile-Xaa-Xaa-Leu-Xaa-Xaa-Xaa-Val (SEQ ID No. 18) and wherein the sequence differs from the native sequence of pST.

Description

CA 022167~ 1997-09-29 W096/30405 PCT~S96~0349a PEPTIDES WITH GROW'TH PROMOTION PRO~K~ S

F;~l~ Qf Th~ Tnv~n t; nn This invention relate~ to peptides which elicit antibodies which ~nh~nce the activity of porcine somatotropin and promote growth of warm-blooded An; m~ 18.

~ch~ ~ ~ Of Th~ Tnvent; nn Porcine somatotropin (pST) is a 191 amino acid long pituitary hormone which has diverse biological activities (Bibliography entry 1). Thîs hormone exists as a single chain polypeptide which is arranged in four anti-parallel a-helices (2). Each a-helix contains 3.6 amino acids per turn. This periodicity places every third or fourth residue on the ~ame face of the helix.
Administration of pST to farm ~n; -18 increases muscle growth, feed efficiency and decreases fat accumulation (3,4). Endogenous amounts of pST are small; therefore, efforts have focused on the preparation of exogenous pST for use in large-scale agriculture. The widespread use of exogenous pST has been hampered by difficulties in formulation and ~m;~; stration. Long-term implants re~uire the stabilization of the pST molecule and control of the release of pST over time. Alternatively, daily or frequent periodic injections of pST involve labor costs which may render the benefits of pST
uneconomical.
Some efforts to reduce these difficulties have involved reducing the amount of pST needed through the addition of a component which potentiates CA 022167~ 1997-09-29 W096/30405 PCT~S96/03490 the activity of pST.
Monoclonal and polyclonal antibodies complexed with somatotropin have been reported to further enh~n~e the biological activity of somatotropin in vivo (5-9). Although the mechanism of antibody-mediated growth ~nh~ncement is not totally clear, altered ph~r~-cokinetics and/or bio-distribution of somatotropin has been proposed in part to explain the growth ~nh~ncement ph~nomenon (10). It has also been suggested that the ~nh~ncement is due to the selective modulation of b;n~;ng to subclasses of somatotropin receptors by the antibodies (5,6,11,12).
Imp ov~ -nt of somatotropin b;n~;ng to hepatic somatogenic receptors was also reported to be a possible explanation (13). It is noteworthy that these antibodies by themselves do not potentiate growth in the absence of exogenous pST.
One attempt to increase ~n; ~'1 growth ; ologically has produced a monoclonal antibody designated PS-7.6, which consistently increases the biological activity of pST in a hypophysectomized (hypox) rat assay (10), even though in the absence of pST it does not by itself increase growth. However, passive ; - ;zation of farm ~n; -18 with this growth-~nh~ncing monoclonal antibody is not optimum economically because of the cost of monoclonal antibody and the labor required for the multiple dosing of antibodies.
Thus, there is a need for a new approach to growth potentiation which will reduce the difficultie~
of the current approaches. One such approach involves the design of peptides which mimic the region of pST
which binds to PS-7.6 monoclonal antibody. The active immunization of ~n; -18 with peptide fragments correspo~;ng to the epitope recognized by PS-7.6 CA 022167~ 1997-09-29 WO 9~/30 ~C~t', PCT/US96/03490 monoclonal antibody should generate antibodies functionally similar to PS-7.6 monoclonal antibody to ~ce the endogenous pST activities. Thus, the identification of the epitope recognized by PS-7.6 monoclonal antibody is critical for the design of peptide vaccines that ~nh~nce ~n; 1 growth performance. Most peptides possess the primary, but lack the secondary conformation of the native protein.
Short peptides typically exist in solution as rapidly interconverting structures (random coils). A
conformation analogous to the desired region of pST
will be present in only a ~mall fraction of the peptides at a given time. Thus, there is a need to design peptides having a defined secon~-y conformation.

~Um~Y Of Th~ Tnv~nt;on Accordingly, it is an object of this invention to design peptides which have well-defined secondary structure, preferably a helical conformation, which mimic the correspon~;ng region of pST.
It is a further object of this invention to design peptides which compete with pST for b;n~;ng to PS-7.6 monoclonal antibody.
It is yet another object of this invention to develop compositions which utilize these peptides for the promotion of growth of warm-blooded ~n; =ls These objects of the invention are accomplished through a peptide which contain~ therein the sequence of amino acids Xaa-Xaa-Leu-Xaa-Xaa-Ile-Xaa-Xaa-Xaa-Leu-Xaa-Xaa-Val-Xaa-Xaa (SEQ ID N0:1), wherein the sequence differs from the native sequence of pST. The invention also include~ peptides wherein CA 022167~ 1997-09-29 W096/30405 PCT~S96/03490 one or more of the first or second leucine or the valine of SEQ ID NO:1 is replaced by normal (straight chain) leucine (Nle). The invention is also directed to a peptide in which the location of the essential amino acids is shifted by three amino acids, representing almost one turn along the helix, which contains therein the sequence of amino acids Xaa-Xaa-Xaa-Xaa-Xaa-Leu-Xaa-Xaa-Xaa-Ile-Xaa-Xaa-Leu-Xaa-Xaa-Xaa-Val (SEQ ID NO:18) and wherein the sequence differs from the native sequence of pST. The peptides of SEQ ID NO:18 are further modified by limiting the third amino acid residue to isoleucine, generating the sequence of amino acids: Xaa-Xaa-Ile-Xaa-Xaa-Leu-Xaa-Xaa-Xaa-Ile-Xaa-Xaa-Leu-Xaa-Xaa-Xaa-Val (SEQ ID NO:19) and wherein the sequence differs from the native sequence of pST.
These peptides preferably contain serine as a promoter of helical conformation as the amino acid ; ~;ately amino-te~m;nAl to the first leucine of SEQ
ID NO:1 and as the amino acid ; -~;ately amino-te ;n~l to the first isoleucine of SEQ ID NO:19.
The peptides of this invention are used with a phA -ceutically acceptable adjuvant, diluent or carrier to formulate compositions in methods for promoting the growth of a warm-blooded An;m~l.

Br;ef Descr~p~; nn Of Th~ F; ~ne8 Figure 1 depicts the trypsin digeRts (lane 1), fractions #9 (lane 2) and #9-5 (lane 3) which are incubated with PS-7.6 monoclonal antibody, ;mm~noprecipitated by magnetized goat anti-mouse IgG
antibody, subjected to SDS-PAGE, electroblotted onto a PVDF membrane, probed with rabbit anti-pST polyclonal antibody followed by iodinated donkey anti-rabbit IgG

CA 022167~ 1997-09-29 WO 96130405 PCT~US96/03490 antibody, and finally exposed to an x-ray film and autoradiography.
Figure 2 depicts the peptides pST(70-95), pST(64-95) and pST(54-95) (Figure 2A), and pST(75-95) and pST(75-90) (Figure 2B), which are synthesized and tested for their inhibitory effects on the interaction between PS-7.6 monoclonal antibody and 125I-pST in a competitive RIA. Cold intact pST is also tested and serves as the positive control.
Figure 3 depicts the results of a radio; s~say which measures the competition for b; n~'; ng to PS-7.6 monoclonal antibody of radiolabelled pST compared with: (1) the pGH(75-95) peptide, (2) a pGH(80-90) peptide, and (3) a pGH(81-90) peptide.
Figure 4 depicts the amino acids of the pST(75-95) fragment, of which amino acid residues 75-90 are sequentially substituted by ~l~n;n~, These analogs are tested by competition RIA. The IC50 of an effective competition for each residue is averaged from five separate experiments.
Figure 5 depicts a helical projection of pST(75-95) of pST. The ~h~e~ circles are the amino acidR critical for the recognition by PS-7.6 monoclonal antibody.
Figure 6 depicts the results of a radio; ~ns~say which measures the competition for b; n~; ng to PS-7.6 monoclonal antibody of radiolabelled pST (referred to as "pGH" in Figure 5) compared with:
(1) a peptide correspQn~'; ng to the native sequence of amino acids 75-95 of pST (referred to as "pGH(75-95)"
in Figure 5), (2) the peptide of SEQ ID N0:2 (referred to as "peptide-Xn), and (3) a modified form of peptide-X where the amino-te~; n~ 1 amino group i8 modified by the addition of an acetyl group (referred to as "capped peptide-X").

CA 022167~ 1997-09-29 W096/30405 PCT~S96/03490 Figure 7 depicts the results of a radioim~no~say which measures the competition for bin~;ng to PS-7.6 monoclonal antibody of radiolabelled pST compared with: (1) the pGH(75-95) peptide, and (2) a peptide of SEQ ID NO:21 not within the scope of this invention (referred to as "peptide-Y" in Figure 6).
Figure 8 depicts the results of a radioi~ o~say which measures the competition for b;n~;n~ to PS-7.6 monoclonal antibody of radiolabelled pST compared with: (1) the pGH(75-95) peptide, (2) peptide-X, (3) peptide-Y, and (4) peptide-X wherein the first leucine iB replaced by nor~-l leucine (Nle), generating SEQ ID NO:13 (referred to as "Nle80" in Figure 7), (5) peptide-X wherein the second leucine is replaced by normal leucine (Nle), generating SEQ ID
NO:14 (referred to as "Nle87n), and (6) peptide-X
wherein the valine is replaced by normal leucine (Nle), generating SEQ ID NO:15 (referred to as "Nle90").
Figure 9 depicts the effect on the growth of hypophysectomized rats receiving either no treatment (negative control, first bar); treatment with pST
alone (positive control, second bar); treatment with pST plus swine antibodies before and after ;~-lln;zation with peptide-X (SEQ ID NO:2) from three different pigs (three groups of rats, third through eighth bars).

De~ ed Descr;pt;~n Of The Tnve~tion This invention comprises the design of peptides which mimic a helical region of pST. These peptides possess minimal sequence homology to pST in order that the peptides can retain a helical CA 022167~ 1997-09-29 WO ~f/~0 ~' PCT/US96/03490 formation. These peptide mimics elicit antibodies which can recognize native pST.
T ln; zation of a target An; ~1 species with a peptide cont~;n;ng the epitope recognized by PS-7.6 - o~lonal antibody (raised against native pST) produces antibodies functionally similar to PS-7.6 monoclonal antibody and promotes the growth of the An; --1, Active immunization of animals with the epitope recognized by PS-7.6 monoclonal antibody is a practical alternative to the passive A~n; n; ~tration of PS-7.6 monoclonal antibody. This idea is supported by a recent report of Pell et al (14) who ~ - ntrated that ;~lln;zation of lambs with somatotropin fragment (residues 135-154), a different region associated with the ~nhAncement, increased the percentage of lean muscle growth.
In this invention, the epitope of pST which binds to PS-7.6 - ~clonal antibody is mapped by a limited tryptic digestion of pST coupled with reverse-phase liquid chromatographic separation and sprecipitation. The critical amino acids of the epitope which interact with PS-7.6 monoclonal antibody are then identified by an; Inologic analysis of a series of sequential alanine analogs of the epitope.
The peptide which contains the epitope recognized by the monoclonal antibody designated PS-7.6, which is raised against recombinant pST, is shown to enhAnce the growth-promoting activity of pST in a hypophysectomized rat -'el and to promote growth in pigs.
A pST fragment correspo~; ng to amino acid residues 70-95 (which contains the second helix of pST
(2)) is separated by reverse-phase high performance liquid chromatography and also; sprecipitated by CA 022167~ 1997-09-29 W096/30405 PCT~S96/03490 PS-7.6 monoclonal antibody. This fragment i8 found in a radioimmunoassay (RIA) to compete with radiolabelled pST for the bi n~; ng to PS-7.6 monoclonal antibody in a dose-dependent fashion. However, sera from pigs immunized with pST(70-95) do not raise significant levels of anti-pST antibodies. This result suggests that the conformation of pST(70-95) does not match that of the true epitope or the peptide is not suf~iciently ; ogenic.
Several peptides covering this potential epitope region of pST(70-95) are synthesized and assayed by competitive RIA. The results suggest that pST(75-95) is the optimal sequence r~o~n;zed by PS-7.6 monoclonal antibody. In contrast, pST(85-95) binds very weakly and non- e~ od~cibly to PS-7.6 monoclonal antibody, while pST(81-95) is completely devoid of b;~;ng. The peptide pGH(80-90) binds almost as strongly as pGH(75-95), while pGH(81-90) binds very weakly to PS-7.6 monoclonal antibody.
Furth~ re, if the peptide is too small, such as pST(80-95), even though b;n~;ng is good, aggregation is substantial due to the hydrophobic character of the individual amino acid residues. To reduce the ay~,eydtion problem and improve solubility, the peptide should be longer.
The design of peptides in the epitopic region pST(75-95) involves a number of factors. Most peptides possess the primary, but lack the secondary conformation of the native protein. Short peptides typically exist in solution as rapidly interconverting structures (r~ coils). A conformation analogous to the desired region of pST will be present in only a small fraction of the peptides at a given time.
The goal of the design is to stabilize the helical conformation and thus to ~nh~nce the affinity CA 022167~ 1997-09-29 w096/30405 PCT~S96/03490 of the antibody for the protein. This affinity requires structural complementarity between the b; n~; ~g site of the antibody and the epitope on the protein.
Amino acid residues which contact the antibody b; n~; n~ site are relatively intolerant of ~ub~titution. Replacement of leucine by isoleucine is ~ufficient to abolish peptide b;n~;ng to the antibody.
Non-critical residues can be replaced by residues which promote or stabilize a desired structure, in this case an a-helix, which allows the peptide to better mimic the native protein conformation.
Among the ~trategies which can be employed to stabilize ~-helices are: (1) interhelical hydrophobic association (15): (2) side-chain charge-charge interactions (16); (3) side-chain co~alent linkages by a disulfide (17) or lactam bond (18); (4) incorporating amino acid residues with high helical propensity (19); (5) charge-helix dipole stabilization (20): (6) end-capping of peptides (21) and metal-ion side chain ~tabilization (22).
The criticality of the first leucine is demonstrated in Example 1 below, where the first leucine of a peptide (SEQ ID N0:2) is replaced by isoleucine to produce the peptide of SEQ ID N0:21. In contrast, non-contact residues may be replaced freely and still bind effecti~ely. Thus, after identifying the essential antibody contact residues, the rem~; n; ng residues of the peptide are replaced 80 as to achieve a stable helical conformation.
Se~uential alanine ~ubstitution of each residue of pST(75-90) re~eals that the residues of Leu80, Ile83 and Leu37, plus either Leu'6 or Val90, are critical for b;n~;ng to PS-7.6 monoclonal antibody (as depicted in the helical projection of Figure 5).
-CA 022167~ 1997-09-29 W09~'30l~ PCT~S96/03490 Other residues are replaced by alanine without substantially altering the bin~;ng affinity. The region of amino acids 75-95 comprises the second helix of pST and the repeating pattern of i and i+3 (i+7) of the critical amino acids appears consistent with PS-7.6 monoclonal antibody b;n~;ng to a hydrophobic side of the helix. This enables peptides to be synthesized utilizing both the i and the i+3 (almost one helical turn) patterns. The sequence and the helical structure of the epitope recognized by PS-7.6 monoclonal antibody provide the basis for designing effective peptide vaccines to enh~nce the growth performance of ~n; ~ 18.
The pST and peptides are generated as follows. Recombinant pST is produced by American Cyanamid Co., Pearl River, NY. Peptides are synthesized on a solid-phase automatic peptide synthesizer (9600, Milligen/Biosearch, Bedford, MA).
All reagents are purchased from Peninsula Laboratories, Inc., Belmont, CA. After being cleaved from the resin support, all peptides are purified by preparative reverse-phase high performance liguid chromatography (HPLC) on a C18 coll-~n (R~; n; n Instrument Corp., Woburn, MA). The purity of these peptides is always greater than 97% as determined by analytical HPLC, FAB mass spectrometry, and amino acid composition analysis. Alternatively, the peptide~ of this invention are also constructed by other technigues known in the art, such as solution-phase chemical synthesis or recombinant expression of a DNA
nucleotide se~uence in an appropriate host.
Recombinant expression may also be in the form of a fusion of the peptide to a carrier, such as a maltose-b; n~; ng protein or peptide.
Mapping of the antibody-recognizing sites CA 022167~ 1997-09-29 W096t3040S PCT~S96/03490 has been appro~he~ conventionally by the enzymatic ~ dige tion of the antigen (23,24) or the concurrent synthesis of multiple peptides on solid supports (25).
Initial attempts with multiple peptide synthesis were not ~uccessful and, therefore, the proteolytic degradation of pST is employed subsequently to complete the epitope mapping of PS-7.6 monoclonal antibody in this study. In the beg;nn;n~, pST is treated at 37~C with various proteases, including chymotrypsin, trypsin and endoproteinase Glu-C. They all produce small pST fragments (m.w. c 4 kDa). The rationale for selecting these small fragments is the convenience of solid pha~e synthesis of future peptide vaccine candidates. However, PS-7.6 monoclonal antibody fails to re~ogn;ze any of these small fr~m~nts by RIA and Western Analysis. In addition, short peptides are generally conformationally flexible and produce a variety of inter-converting configurations in solution. As a result, resulting anti-peptide antibodies frequently interact with the correspon~; ng native protein with a very low efficiency.
Results from the initial experiments of enzymatic degradation indicate that the epitope recognized by PS-7.6 monoclonal antibody is very sensitive to protease at 37~C. It is possible that the se~n~y/tertiary structure of pST might be slightly unfolded at this temperature, thus exposing the critical epitope region to the protea~e for a total degradation. In order to limit the degree of enzymatic digestion to protect the intact PS-7.6 epitope, especially the loops and turns (26), the reaction temperature is restricted at 25~C for three days.
Specifically, recombinant pST (100 mg) is CA 022167~ 1997-09-29 W096/30405 PCT~S96/03490 subjected to limited tryptic digestion by incubation with 1 ml bo~ine pancreatic trypsin cross-linked to agarose (50 units enzymatic activity per ml of packed gel, Sigma Co., St. Louis, MO) in 200 ml phosphate buffer, pH 9.5, at 25~C for three days. The tryptic fragments are separated by preparative HPLC (C18 column, 21.4 mm x 25 cm, flow rate = 24 ml/min., W at 235 nm., Dynamax-300A, R~;n;n) with a linear gradient of 0-100% of B buffer in 30 minutes (A buffer = 0.1%
TFA in water; B buffer = 0.1% TFA in acetonitrile).
All fractions are collected and analyzed by RIA to identify the acti~e cnmron~nts. A predominant and stable tryptic fragment which is ab~ent in the 37~C
digestion is produced and designated as fraction #9.
This fraction is eluted at a retention time of 18.89 minutes and comprises more than 60% yield of the initial pST digestion. It is later found to compete with l25I-pST for the b;n~;ng to PS-7.6 monoclonal antibody in RIA, suggesting that the fraction #9 contain~ the PS-7.6 epitope. The fraction #9 is further reduced by a 10 molar excess of dithiothreitol in 0.1 M ~ - ;um bicarbonate solution at pH 9.5 and again fractionated by HPLC. One fraction, designated #9-5 and eluted at a retention time of 18.43 minute~, continues to exhibit an ability to compete with l25I-pST
for PS-7.6 monoclonal antibody b; n~; ng.
A combination of ; oprecipitation and Western blotting experiments is carried out to analyze these samples. The trypsin digests, fractions #9 and #9-5, are incubated with PS-7.6 monoclonal antibody for 60 minutes at 37~C. I~~gnetic beads coated with goat anti-mouse IgG (Advanced Magnetics Inc., Cambridge, MA) are added to the mixture and incubated for 30 minutes at room temperature with gentle, constant ~h~k;ng. The beads are washed several times CA 022l67~ l997-09-29 WO 96/30405 PCT/US96/~3490 and collected by a ~gret. The protein~ are separated ~ from the beads by boiling in SDS-PAGE 8ample buffer and ~ub~ected to reduced Tri~-tricine polyacrylamide gel electrophoresi~ on a 16% gel (PAGE, Novex, San Diego, CA). The separated protein components are electroblotted from the gel onto a polyvinylidene difluoride microporous (PVDF) membrane (Applied Biosystems, Foster City, CA) in a 10 mM 3-[cyclohexyl r- ;no] -l-propane~ulfonic acid (CAPS) buffer at pH ll contA;n;ng 20% methanol. The membrane is treated with 5% nonfat milk followed by sequential expo~ure~ to rabbit anti-pST polyclonal antibody and 0 iodinated donkey anti-rabbit IgG antibody (Amersham Corp., Arlington Heights, IL). The PVDF membrane in finally expo~ed to an x-ray film for the development of autoradiography. To determine the amino acid ~equence of the tryptic fragment~, the m~mhrane blot~
are ~tA;ne~ briefly with a solution contA;n;ng 0.1%
Coomassie, 40% methanol and 10% acetic acid and the visible bands are exci~ed. These bands are arranged in a single layer in the upper cartridge block of a gas-phase sequenator (Applied Biosystems) and the phenylthiohydantoin-derived amino acids are dete~m;neA
by the procedure of ~AnkApiller ~ Hood (27). The results are seen in Figure 1.
It i~ clear that the predominant component of pST after a limited digestion with trypsin is the 15 kDa material with minor cont~;n~nts of 10 kDa, 4 kDa and 2.5 kDa (lane 1). However, the~e minor components are enriched and become pr~m;n~nt in fraction #9 following HPLC fractionation (lane 2).
Finally, the 2.5 kDa fragment appears to be the only cl _- ~nt present in the fraction #9-5, sugge~ting that the epitope recognized by PS-7.6 monoclonal antibody re~ides within this fraction (lane 3). The =
CA 022167~ 1997-09-29 W096l30405 PCT~S96/03490 2.5 kDa fragment i8 then seguenced and found to correspond to amino acids 70-95 of pST. The chemical structure and ; ologic properties of this fragment are confirmed by a solid phase peptide synthesis (28), because the synthesized peptide is capable of competing with 12sI-pST in a dose dependent fashion for the b;n~;ng to PS-7. 6 monoclonal antibody in RIA
(Figure 2). The competition by pST (70-95) is d~ Gximately 100-fold less active than that by cold pST.
In order to further characterize the preci~e epitope, three additional peptides are synthesized.
Peptides pST (54-95) and pST(64-95) are produced by ext~n~; ng the amino acid residues of the N-terminu~, while pST (75-90) is generated by truncating the residues at both ends. These peptides are tested in RIA and exhibit a similar competition effect as c~ _-~ed to the tryptic pST (70-95) fragment, suggesting that the residues between 75 and 90 contain the epitope (Figure 2). The competition of these peptides is substantially lower than that of a control pST, probably due to the conformational flexibility inherent in the short peptides and the involv - t of other discontinuous residues in the antibody recognition.
A separate competition RIA establishes the criticality of the Leu80 residue. As depicted in Figure 3, the peptide pGH(80-90) binds almo~t as strongly as pGH(75-95) ~ while pGH(81-90) binds very weakly to PS-7. 6 monoclonal antibody.
The conformational flexibility of peptide antigens limits their practical utility as antigens. t However, the limitation can be overcome by restricting the conformational flexibility of the peptides to mimic the secondary structure of the native protein CA 022167~ 1997-09-29 w096J3040s PCT~S96/03490 .

anti~en. It is also known that not every residue in ~ an epitope is neceQsarily in contact with the antibody b;n~;ng sites (29). Because the seco~ry structure ~ of the PS-7.6 monoclonal antibody epitope is considered important, the amino acid side ~h~;n~ of the pST(75-95) fragment that interact with PS-7.6 monoclonal antibody are det~_ ;n~ by sequentially replacing each residue with ~1 ~n; ne. The ~equential substitution with alanine, which ha_ a high propensity to form a helical conformation in peptides or proteins (30), is less likely to change the accessible backbone conformation of pST(75-95).
This approach, called ~l~n;ne-8c~nn;ng mutagenesis, ha~ been very useful for identifying the critical amino acids of human somatotropin which interact with its receptor (31). Al ~n;ne is ascumed to leave the seco~y structure ~nch~nged, while eliminating one potential site of interaction with the antibody. If the peptide contA;n;ng a substituted alanine still binds to the antibody, the replaced amino acid iQ considered to be a non-contact residue.
Therefore, a ~eries of ~l~n;ne-substituted analogs of pST(75-90) is Qynthesized by the solid-phase method and their ability to compete for PS-7.6 monoclonal antibody b;n~;ng with pST is evaluated by RIA. Side ch~;nQ of residues are considered critical if the ~l~n;n~ replacement results in a significant increase in IC50 to achieve an equivalent competition.
F;n~;ngs in Figure 4, which are ~ -~ized from five separate experiments, indicate that Leu80 (see also Figure 3), Ile83 and Leu37, which all are hydrophobic amino acids, are critical to PS-7.6 - o~lonal antibody recognition, and that either Leu76 or Val90 is al_o critical. Although the bar value for position 89 3S i8 greater than that for position 90 in Figure 4, when CA 022l67~ l997-09-29 W096/30405 PCT~S96/03490 p values are computed using Fisher'~ combined p-value test, the p value for position 90 is statistically significant (p=0.00162), while the p value for position 89 is not statistically significant (p=0.16048). Note that Figure 4 does not include the data from a sixth experiment, where the results are entirely inconsistent with the other five experiments.
Based on the tertiary structure of pST (2) and the projection of the second helix, these five critical residues presented by the ~ e~ circles in Figure 5 are located on the same face of the helix, representing a hydrophobic ribbon to interact with PS-7.6 monoclonal antibody.
In s~ary, the epitope of growth-~nh~cing antibody PS-7.6 monoclonal antibody is mapped by a limited tryptic digestion and the critical amino acids on the epitope are identified by the sequential alanine substitution. The a-helical projection of pST
shows that the critical amino acids are a hydrophobic ribbon located on the same face of the second helix.
The characterization of the sequence and secondary structure of the epitope provide the basis for designing effective peptide antigens that mimic the native conformation of the correspQ~;ng epitope of pST.
Based on the identification of critical amino acids in the epitope, a series of peptides is designed. In one embodiment of the invention, the peptides are selected from sequences cont~;n;ng the formula:
Xaa-Xaa-Leu-Xaa-Xaa-Ile-Xaa-Xaa-Xaa-Leu-Xaa-Xaa-Val-Xaa-Xaa (SEQ ID NO:1) wherein the sequence differs from the native sequence of pST. Examples of such peptides include:
Tyr-Ser-Leu-Asp-Asp-Ile-Ile-Arg-Arg-Leu-Asp-CA 022167~ 1997-09-29 Asp-Val-Ile-Arg-Arg-Ile (SEQ ID N0:2), Tyr-Ser-Leu-Asp-Arg-Ile-Ile-Arg-Asp-Leu-Asp-Arg-Val-Ile-Arg-Asp-Ile (SEQ ID N0:3), Tyr-Ser-Leu-Arg-Arg-Ile-Ile-Arg-Arg-Leu-Arg-Arg-Val-Ile-Arg-Arg-Ile (SEQ ID N0:4), Tyr-Ser-Leu-Asp-Asp-Ile-Ile-ARp-Asp-Leu-Asp-Asp-Val-Ile-Asp-Asp-Ile (SEQ ID N0:5), Tyr-Ser-Leu-Anp-Anp-Ile-Ala-Arg-Arg-Leu-Asp-Asp-Val-Ala-Arg-Arg-Leu (SEQ ID N0:6), Tyr-Ser-Leu-Lys-Ala-Ile-Ala-Glu-Ala-Leu-Lys-Ala-Val-Ala-Glu-Ala (SEQ ID N0:7), Tyr-Ser-Leu-Ly~-Glu-Ile-Glu-Lys-Leu-Leu-Lyn-Glu-Val-Leu-Glu-Ly~-Leu (SEQ ID N0:8), Tyr-Ser-Leu-Asp-Asp-Ile-Ala-Arg-Arg-Leu-Asp-A~p-Val-Ala-Arg-Arg-Ala (SEQ ID N0:9), Tyr-Ser-Leu-Lys-Ile-Ile-Ile-Glu-Ile-Leu-Lys-Ile-Val-Ile-Glu-Ile (SEQ ID N0:10), Tyr-Ser-Leu-Lys-Glu-Ile-Glu-Lys-Leu-Leu-Lys-Glu-Val-Leu-Glu-Lys-Leu (SEQ ID N0:11), and Tyr-Ser-Leu-Lys-Aib-Ile-Aib-Glu-Aib-Leu-Lys-Aib-Val-Aib-Glu-Aib (SEQ ID N0:12), where Aib i~ 2-aminoisobutyric acid.
In addition, one or more of the leucines or ~aline of SEQ ID N0:1 can be replaced by no ~1 leucine (Nle), an follows:
Tyr-Ser-Nle-Asp-Asp-Ile-Ile-Arg-Arg-Leu-Asp-Asp-Val-Ile-Arg-Arg-Ile (SEQ ID N0:13), Tyr-Ser-Leu-Asp-Asp-Ile-Ile-Arg-Arg-Nle-Asp-Asp-Val-Ile-Arg-Arg-Ile (SEQ ID N0:14), Tyr-Ser-Leu-Asp-Asp-Ile-Ile-Arg-Arg-Leu-Asp-Anp-Nle-Ile-Arg-Arg-Ile (SEQ ID N0:15), and Tyr-Ser-Nle-Asp-Asp-Ile-Ile-Arg-Arg-Nle-Asp-A~p-Val-Ile-Arg-Arg-Ile (SEQ ID N0:16).
Fur~h~ -re, a cysteine may be ~ to either or both ends of the peptiden of SEQ ID N0:1.

CA 022167~ 1997-09-29 WO 96/301'~ PCTIUS96/03490 An example of such a peptide is:
Cy~-Tyr-Ser-Leu-Asp-Asp-Ile-Ile-Arg-Arg-Leu-Asp-Asp-Val-Ile-Arg-Arg-Ile (SEQ ID N0:17).
In another .e ~o~; ~nt of the invention, the location of the essential amino acid residues is shifted by three amino acids, representing almost one turn along the helix. These peptides are selected from sequences cont~; n; ng the formula:
Xaa-Xaa-Xaa-Xaa-Xaa-Leu-Xaa-Xaa-Xaa-Ile-Xaa-Xaa-Leu-Xaa-Xaa-Xaa-Val (SEQ ID NO:18) wherein the sequence differs from the native sequence of pST. In particular, these peptides include an isoleucine as the third residue and are selected from sequences cont~; n; ng the formula:
Xaa-Xaa-Ile-Xaa-Xaa-Leu-Xaa-Xaa-Xaa-Ile-Xaa-Xaa-Leu-Xaa-Xaa-Xaa-Val (SEQ ID NO:l9) wherein the seguence differs from the native sequence of pST. An example of such a peptide i8:
Tyr-Ser-Ile-Asp-Asp-Leu-Ile-Arg-Arg-Ile-Asp-Asp-Leu-Ile-Arg-Arg-Val (SEQ ID NO:20).
TheQe peptides preferably contain serine as a promoter of helical conformation as the amino acid ; ~~;ately amino-t~m;n~l to the first leucine of SEQ
ID N0:1 and as the amino acid ; -~;ately amino-t~r~;n~l the first isoleucine of SEQ ID N0:19.
The amino acid sequences of these peptides are described using the convention that the first essential residue is toward the amino-terminus and the last essential residue is toward the carboxy-terminus.
The invention also encompasses identical sequenceQ in opposite orientations where the first essential residue is toward the carboxy-te~m;nl~Q and the last essential residue is toward the amino-te~;nnQ. Both orientations have the same helical projection on the side chain (see Figure 5 ) and are functionally CA 022167~ 1997-09-29 WO 96130405 PCT~US96/03490 equivalent.
- other peptides within the scope of the invention are generated readily by uRing the methods and criteria described herein.
The peptide~ of this invention are tested in various experiments, as described in detail in the Examples below.
Fir~t, radioimmunoassay~ are performed to determine the extent to which various peptides (both within and outside the scope of this invention) compete with radiolabelled pST for b;n~;ng to PS-7.6 - ~clonal antibody. As detailed in Example 1 and shown in Figure 6, the peptide of SEQ ID NO:2 (referred to as "peptide-X") inhibits the interaction of ~S-7.6 ~no~lonal antibody and radiolabelled pST in a dose dependent manner more strongly than a peptide corre8p~n~; ng to the native sequence of amino acids 75-95 of pST. A modified form of peptide-X, where the amino-teTm;nA1 amino group i8 replaced by an acetyl group (referred to as "capped peptide-X") does not inhibit the interaction. In experiments not shown in Figure 6, the peptide~ of SEQ ID NOS:8-11 inhibit the interaction as well as peptide-X, while the peptides of SEQ ID NOS:3 and 12 inhibit the interaction, but at a lower rate than peptide-X.
As detailed in Example l and shown in Figure 7, a peptide not within the scope of the invention and having the sequence Tyr-Ser-Ile-Asp-Asp-Ile-Ile-Arg-Arg-Ile-Asp-Asp-Ile-Arg-Arg-Ile (SEQ ID NO:21;
referred to as "peptide-Y") is much less effective in inhibiting the interaction than the pGH(75-95) peptide. Thus, the substitution of isoleucines for the first leucine and the valine in the peptide of SEQ
ID NO:2 abolishes the b;n~;~g to the antibody.
As detailed in Example l and shown in Figure CA 022l67~ l997-09-29 W096/30405 PCT~S96/03490 8, peptide-X and three variants thereof (SEQ ID
NOS:13-15) where the leucines or valine are replaced by normal leucine (Nle) are more effective than pGH(75-95) in inhibiting the interaction, whereas peptide-Y is again much less effective. In an experiment not shown in Figure 8, the peptide of SEQ
ID NO:16 inhibits the interaction as well as peptide-X.
Next, the biological activity of these peptides is tested in hypophysectomized (hypox) rats.
Hypox-rats are growth-deficient as a result of surgical ~ vdl of their pituitary glands. Hypox-rats serve as a useful model for studying the effect of somatotropin on growth (32).
As described in Example 2 and shown in Figure 9, peptide-X (SEQ ID NO:2) is conjugated to ovalbumin and emulsified in Complete Freund's Adjuvant. Three pigs are ; ;zed with peptide-X and receive two booster doses with Incomplete Freund's Adjuvant. Blood samples are taken from thege ~n;m~l 8 and control sera are al~o harvested from the same pigs prior to the first injection. Antibodies are purified, mixed with pST and injected into hypox rats for five consecutive days. Rats receiving pST alone grow in a statistically signficant manner. Rats receiving pST plu8 antibodies from pigs #1 or #2 after ; ni zation have significantly increased growth.
Although the effect of the antibodies from pig #3 does not reach a statistically significant level (p=0.08), there is visible growth ~nh~ncement. In contrast, pre-; ;zation antibodies are not effective. As a result of the hypox rat experiments, ; ;zation trials are conducted with pigs.
Peptides may be administered alone or, more preferably, linked to a macromolecule which serves to CA 022l67~ l997-09-29 WO 96/30405 PCT/US96~03'~9a ~nh~nce the production of antibodies in ~ vo. For ~ example, the peptide may be conjugated to a protein such as keyhole limpet haemocyanin (RLH). Other macromolecules within the scope of this invention include those known in the art such as hl -n and bovine 6erum albumins, ovalbumin, myoglobins, ~-galactosidase, penicillanase, heat shock protein and bacterial toxoids. Synthetic molecules such as multi-poly-DL-alanyl-poly-L-lysine and poly-~-lysine are also suitable.
The peptides may be A~m; n; stered by conventional routes such as subcutaneous injection, intramuscular injection and intravenous flow, as well as trans~e ~l and oral administration. It is preferred to administer the peptides (or their conjugates) in association with a ph~ ceutically acceptable adjuvant, diluent or carrier. It is particularly preferred to use a dosage regimen where an initial ~m;n; stration of the peptides is followed by one or more booster ~; n; stration of the ~ame peptides at regular time intervals.
As detailed in Examples 3-5, the ; ;zation of pigs with the peptides of this invention results in the desirable results of an increase in feed efficiency, and an increased lean and decreased fat.
In Example 3, Table 1, finishing pigs receiving the peptide of SEQ ID NO:2 have a statistically significant increase in feed efficiency over the course of the experiment when compared to pigs receiving o~albumin only. In Example 3, Table 2, the aame pigs receiving the peptide display improved carcass characteristics, with a statistically significant increase in lean and decrease in fat when compared to pigs receiving ovalbumin only. It is CA 022l67~ l997-09-29 W096/30405 PCT~S96/03490 interesting to note that the pigs receiving the peptide do not have a significant increase in most organ weights. In contrast, pST is known to increase organ weights.
When the experiment of Example 3 iB repeated in Example 5 with another group of finishing pigs receiving either the peptide of SEQ ID NO:2 or the peptide of SEQ ID NO:17 ("Cys-Peptide"), both groups of pigs have a statistically significant decrease in undesirable leaf fat when compared to pigs receiving ovalbumin only, while the pigs receiving the peptide of SEQ ID NO:2 have a statistically significant decrease in semit~n~;nosis (see Tables 5 and 6).
In Example 4, Tables 3 and 4, growing pigs receiving the peptide have a statistically significant increase in lean over the course of the experiment when compared to pigs receiving ovalbumin only. This is particularly significant during the treatment stages, as compared to the finishing period where treatment i~ ~topped.
In order that this invention may be better understood, the following examples are set forth. The examples are for the purposes of illustration only and are not to be construed as limiting the scope of the invention.

P!y~ e 1 Cn~?etitive Radioi m"~ln~assay Radio; lno~says are performed to determine the extent to which various peptides compete with radiolabelled pST for b;n~;~g to PS-7.6 monoclonal antibody. For any given concentration of peptide, the lower the amount of pST which binds to the antibody in the assay, the greater the competition of the peptide to the antibody. Peptides which conformationally CA 022167~ 1997-09-29 W096/30405 PCT~S96/03490 mimic native pST ~hould diQplace pST from PS-7.6 ~ monoclonal antibody more efficiently. The radio; O~Qays are performed aQ followR.
oble microtiter wellQ are coated with PS-7.6 monoclonal antibody at 1 ~g/well and the r~m~;n;n~ microtiter well b;n~;n~ sites are blocked with 2% BSA. Iodinated pST (lZ~I-pST, specific activity = 180-250 ~Ci/~g, New England Nuclear/DuPont, Co., BoRton, M~) iQ added together with competitive agents at various dilution~. After a 60 minute incubation, all wells are washed thoroughly to ~_~ve the unbound 5I-pST and the re~idual radioactivity, reflecting the amounts of l25I-pST which remain associated with PS-7.6 monoclonal antibody in each well, iQ counted individually in a gamma counter.
In a first experiment depicted in Figure 6, a radio; ~ay iR performed which mea~ure~ the competition for b;n~;n~ to PS-7.6 monoclonal antibody of radiolabelled pST (referred to aQ "pGH" in Figure 6) compared with: (1) a peptide corresp~n~;ng to the nati~e sequence of amino acids 75-95 of pST (referred to a~ "pGH(75-95) n in Figure 6), (2) the peptide of SEQ ID N0:2 (referred to as "peptide-X"), and (3) a modified form of peptide-X where the amino-te ;n~l amino group is replaced by an acetyl group (referred to a~ "capped peptide-Xn).
The results indicate that addition of pGH(75-95) to the wells inhibits the interaction of PS-7.6 monoclonal antibody and radioactive pST in a 3~ dose dependent manner. Peptide-X iQ alQo ~hown to inhibit the interaction in a ~imilar, though somewhat Qtronger, fashion, whereas capped peptide-X fails to do 80. Without being bound by theory, the failure of capped peptide-X in the competition assay may be due to the inter-peptide aggregation in the test solution.

CA 022167~i~i 1997-09-29 WO 95/30 lI!r PCTtUS96/03490 In a second experiment depicted in Figure 7, a radioimmunoassay i8 performed which measures the competition for b;n~;ng to PS-7.6 monoclonal antibody of radiolabelled pST compared with: (1) the pGH(75-95) peptide, and (2) a peptide of SEQ ID N0:21 not within the scope of this invention (referred to as "peptide-Y" in Figure 7).
The results indicate that addition of pGH(75-95) to the wells inhibits the interaction of PS-7.6 monoclonal antibody and radioacti~e pST in a dose dependent -nne~. In contrast, peptide-Y is shown to be much less effective.
In a third experiment depicted in Figure 8, a radio; o~say is performed which measures the competition for b;n~;ng to PS-7.6 monoclonal antibody of radiolabelled pST ro~r~ed with: (1) the pGH(75-95) peptide, (2) peptide-X, (3) peptide-Y, (4) peptide-X wherein the first leucine is replaced by normal leucine (Nle), generating SEQ ID NO:13 (referred to as "Nle80" in Figure 8), (5) peptide-X
wherein the second leucine is replaced by normal leucine (Nle), generating SEQ ID NO:14 (referred to as "Nle87"), and (6) peptide-X wherein the ~aline is replaced by normal leucine (Nle), generating SEQ ID
NO:15 (referred to as "Nle90").
The results indicate that addition of pGH(75-95) to the wells inhibits the interaction of PS-7.6 monoclonal antibody and radioactive pST in a dose dependent ~-nner. Several peptides within the scope of this invention, including peptide-X, Nle80, Nle87 and Nle90, are found to be more effecti~e than pGH(75-95) in this competition assay. However, peptide-Y is again shown to be much less effective.

CA 022167~ 1997-09-29 E~~le 2 ~em~nt Of pST Act;v;ty Tn ~ypox ~t8 W; th SW;n~ Ant~h~A;es To A Pept;~
In this example, swine are injected with a peptide. Serum samples cont~;n;ng ant;hoA;es raised against the peptide are injected together with pST
into hypox rats. The ant;~oA;es potentiate the ability of pST to promote the growth of the hypox rats. The experiment is conducted as follows.
Peptide-X (SEQ ID NO:2) is conjugated to ovalbumin and e_ulsified in Complete Freund' 8 Adjuvant. Three pigs are ; ;zed with peptide-X and receive booster doses with Incomplete Freund's Adjuvant four and eight weeks thereafter. Blood samples are taken from these ~n ; - 18 one week after the last boosting. Control sera are also harvested from the same pigs prior to the first injection.
Antibodies are purified by ; - ;um sulfate precipitation, m; Ye~ with pST to provide a dose of 1 mg antibodies and 5 ~g pST, and injected into hypox rats for five consecutive days. Three separate groups of rats each receives ant;hoA;es from one different pig; a fourth group of rats receives no injections, while a fifth group of rats receives only pST. The net weight gains of the rats of day 5 are depicted in Figure 9.
Treatment with pST alone stimulates growth in hypox rats in a statistically signficant ~~nner (*, pcO.05). Rats receiving pST plus antibodies from pigs #1 or #2 after immunization have significantly increased growth. Although the effect of the antibodies from pig #3 does not reach a statistically significant level (p=0.08), there is visible growth ~nh~cement. In contrast, pre-; ;zation antibodies are not effective.

CA 022l67~ l997-09-29 W096/3040S PCT~S96/03490 Ex~mple 3 n; zat; ~n of F; n; ~h; n~ ~; gs With A Peptide This example sets forth the effects of immunization of finishing pigs (final growth phase from 70-80 kg and above) with a peptide of this invention on growth rate, feed efficiency and carcass composition.
The peptide (Tyr-Ser-Leu-Asp-Asp-Ile-Ile-Arg-Arg-Leu-Asp-Asp-Val-Ile-Arg-Arg-Ile; SEQ ID NO:2) is synthesized and conjugated to ovalbumin. For comparison, on ovalbumin antigen is generated by conjugating ovalbumin to itself.
Mixed-breed barrows (a new commercial DeRalb term;nAl cross genetic line) weighing 70-80 kg are purchased from Gold Rist Pork, Hillsborough, NC. Pigs are the target ~n; 1 for the peptides and at least 25 pigs per treatment group are needed to obtain statistical significance between treatment8. An;m~l 8 are individually identified by numbered eartags and maintained in numbered pens. The pigs receive a diet which is medicated with chlortetracycline at 200 g/ton and are fed for about one week after the pigs are delivered. The pigs receive a Swine ST ration (20%
crude protein) for the rr~ e~ of the experiment.
Feed and water are available ad libitl-m.
An; ~18 are assigned to each of the two treatments in a rAn~ ;zed complete block design. The An;m~l 8 are blocked by initial body weight. The following treatments are ~m;n; stered:
GrQUp An~;g~n n N~mher Pen~
A Ovalbumin/ovalbumin 25 5 B Peptide/ovalbumin 25 5 The pigs are rAn~mly assigned to treatment groups A
or B within each of the blocks. Each block of 15 pigs start treatment when their average body weights are CA 022167~ 1997-09-29 about 75 kg.
The pigs are allowed at least a 1-week pretreatment period in the pen~ before the first ; ;zation injection. The flow of feed is adjusted to pro~ide unlimited access with a minimum of wastage.
Pigs are ; ;zed with 0.5 mg of peptide/ovalbumin conjugate totally emulsified with Complete Freund's Adjuvant using a subcutaneous (SC) injection in the neck area ju~t behind the ear~. All pigs receive one booster injection after a 4-week interval using the same quantity of conjugate, but with Incomplete Freund'~ Adjuvant. Control pigs receive the ovalbumin conjugate without the peptide.
Pigs are observed daily. Any ~ick or injured An; ~18 receive appropriate veterinary care.
An; -18 that do not recover within a few days or that are isolated to recover (e.g. lameness that is aggravated by penmate~) are -ved from the experiment.
Body weights and feed con~umption are determined weekly and more often if necessary as the pigs approach the slaughter weight.
Each pen of pigs is sacrificed when the mean live weight is 115+2 kg. Carcass measurements include chilled weight, backfat thickness, rib eye area, carcass length and weights of heart, liver, spleen, kidney, leaf fat and semit~n~;nous muscle.
The data are analyzed using the analysis of variance procedures for a rAn~ ;zed complete block design. The experimental unit for the evaluation of weight gain and carcass measurement~ is the individual pig. Feed consumption and feed efficiency data use the pen as the experimental unit. Mean comparisons are made using Fisher's Protected LSD.
The experiment proceeds on the following CA 022167~ 1997-09-29 W O 96/30405 PCTrUS96/03490 srhe~le. On Day 1, all pigs are weighed and treatment (including the initial immunization for Group B) starts for each block when the average body weight reaches 75 kg.
Booster injections are :~m;n; stered 4 and 8 weeks after the initial immunization. Pigs are weighed and feed consumption iB dete~m;ne~ on a weekly basis. The pigs are then sacrificed at mean pen weights of 115i2 kg.
The results of this experiment are shown in Tables 1 and 2.

CA 022l67~ l997-09-29 W096/30405 PCT~S96/03490 Table 1 -The effects of active immunization of finishing pigs with a peptide on growth, feed consumption and feed efficiency Control T 1~; zed SEM
Item Ova/ova Peptide No. pens/pigs 5/25 5/25 Body weight, kg Initial 76.2 76.3 0.3 4 Weeks 99.2 98.8 0.8 Final 116.2 117.1 1.0 Days on Experiment51.2 51.0 1.3 Gain, g/day 1-4 Weeks 819 804 26.9 5 Weeks - End 743 805 27.5 1 Week - End 781 802 18.4 Feed intake, g/day 1-4 Weeks 3390 3250 59.7 5 Weeks - End 3316 3326 93.4 1 Week - End 3357 3285 54.5 Gain/Feed 1-4 Weeks .241 .247 .005 5 Week~ - End .222 .242 .009 1 Week - End .233 .244* .004 * Significantly different than control, Pc.05 CA 022l67~ l997-09-29 W096/30405 PCT~S96/03490 Table 2 The effects of active ; ;zation of finishing pigs with a peptide on carcass measurements and organ weights ItemControl Immunized SEM
Ova/ova Peptide No. pens/pigs 5/25 5/25 Carcass weight, kg82.5 82.2 .8 Dressing percent 71.0 70.2 .3 Carcass length, cm82.6 83.0 .4 Organ weight, g Heart 370 373 8.6 Liver 1804 1829 37.8 ~idneys 375 384 8.7 Spleen 161 175 6.6 Leaf fat 1663 1389** 60.9 Semit~n~;nosus 394 434*** 8.2 Fat thickness, cm 1st rib 4.9 4.4* .14 Last rib 2.9 3.0 .10 Lumbar 2.6 2.3 .12 Backfat 3.5 3.2 .09 6th rib 3.6 3.1** .11 10th rib 3.7 3.2*** .11 Adjusted 10th rib 3.3 2.8*** .1 fat, cm Loin eye area, cm244.2 44.6 .8 Adjusted loin eye 41.6 41.9 .8 area, cm Calculated lean (33) Kg 38.1 39.7** .4 % 56.1 57.6* .5 * Significantly different than control, Pc.05 ** Significantly different than control, Pc.01 *** Significantly different than control, Pc.001 CA 022l6755 l997-09-29 W096l30405 PCT~S96/03490 Ex~le 4 ~n;7~t.;on Of Grow;n~ P;g~ W;th A Pept~
The immunization experiment of Example 3 is repeated using young growing pigs (approximately 15-20 kg) from the herd of American Cyanamid Company, Princeton, NJ. Two booster injections are given at four week intervals (during the growth phase to approximately 50-60 kg). The ~n;~l~ are then maint~;neA to sacrifice at a finishing weight of approximately 115 kg. The re~ults of this experiment are ~hown in Tables 3 and 4.

CA 022l67~ l997-09-29 W096/3040S PCT~S96/03490 Table 3 The effects of active ; ;zation of growing pigs with a peptide-on growth, feed consumption and feed efficiency Item ControlT~--n; zed SEM
Ova/ova Peptide No. pens/pigs 6/27 6/26 Body weight, kg Initial 18.5 18.8 .3 4 Weeks 39.8 40.7 .6 8 Weeks 56.3 59.1* .8 12 Weeks 72.9 76.3* 1.1 16 Weeks 97.6 100.7 1.4 Final 113.0 114.1 1.5 Days on Experiment135.0 131.2+ 1.4 Gain, g/day 1-4 Weeks 762.0 782.2 13.4 1-8 Weeks 675.4 718.9* 11.6 1-12 Weeks 647.8 683.7 12.3 1-16 Weeks 706.3 730.7 11.6 1 Week - End 704.0 728.5 11.6 8 Weeks - End 725.1 735.2 16.4 Lean tissue (34)326.6 343.6* 5.8 Feed Intake, g/day 1-4 Weeks 1702 1632 37.2 1-8 Weeks 1670 1631 52.1 1-12 Weeks 1843 1857 70.5 1-16 Weeks 2131 2187 72.0 1 Week - End 2352 2401 70.6 8 Weeks - End 2872 3061 89.2 Gain/Feed 1-4 Weeks .448 .480*.011 1-8 Weeks .404 .444*.013 1-12 Weeks .351 .371.010 1-16 Weeks .331 .337.011 Week 1 - End .298 .305.010 Week 8 - End .251 .242.009 Lean ti~sue (34).137 .144.005 + Significantly different than control, Pc.10 * Significantly different than control, Pc.05 CA 022167~ l997-09-29 WO~l30~' PCT~S96/03490 Table 4 The effects of active immunization of growing pigs with a peptide on carcass measurements and organ weights Item Control T ;zed SEM
Ova/o~a Peptide No. pen~/pigs 6/27 6/26 Carcass weight, kg79.8 80.6 1.1 Dressing percent71.1 71.0 .3 Carcass length, cm83.2 83.5 0.5 Organ weight, g Heart 400 439* 10.9 Li~er 1796 1841 33.3 Ridney~ 387 385 8.5 Spleen 150 158 5.0 Leaf fat 1441 988*** 54.7 Semit~n~;no is 425 461* 12.1 Fat thickness, cm 1st rib 4.3 4.2 .16 Last rib 2.2 2.2 .09 Lumbar 2.2 2.0 .09 Backfat 2.9 2.8 .09 6th rib 2.1 2.0+ .07 10th rib 2.7 2.5* .08 Adjusted 10th 2.5 2.2* .07 rib fat, cm Loin eye area, cm238.2 42.1** .8 Adjusted loin eye36.4 40.0*** .7 area, cmZ
Calculated lean (33) Rg 39.9 41.1** .3 % 56.2 58.5*** .4 + Significantly different than control, Pc.10 * Significantly different than control, P~.05 ** Significantly different than control, P~.01 *** Significantly different than control, P~.001 W 096/30405 PCT~US96/03490 ~le 5 ;7at;~n of ~;n;~h;n~ Pi~s With ~ Pept;de The ; ln; zation experiment of Example 3 is repeated with the inclusion of a second peptide having a cystine linkage at the amino-term;nl~ (SEQ ID
NO:17)(Cys-peptide), which is conjugated to ovalbumin as follows: Ovalbumin (10 mg) is dissolved in an aqueous solution (pH 8) and treated with iodoacetic anhydride (16 mg; 20-fold excess) and stirred for 2 hours at ~hient temperature. The excess iodoacetic anhydride-is separated by ultrafiltration and the modified ovalbumin is reacted with the Cys-peptide for four hours at ~hient temperature and dialyzed to produce the final conjugate. The results of this experiment are shown in Tables 5 and 6. Note that two pigs receiving the conjugated Cys-peptide died during the course of the study.

CA 022l6755 l997-09-29 W096l30405 PCT~S96103490 Table 5 The effect~ of active ; ;zation of finishing pigs with peptide~ on growth, feed con~umption and feed efficiency Control Immunized T ; zed SEM
Item Ova/ova Peptide Cys-Peptide No. pen~/pigs 5/25 5/25 5/23 Body weight, kg Initial 76.6 76.7 76.7 0.3 4 Week~ 100.8 102.2 102.2 0.9 Final 119.2 119.2 120.1 1.2 Day~ on Experiment49.8 49.0 48.4 1.2 Gain, g/day 1-4 Week~ 866 909 903 30.2 4 Weeks - End 845 811 896 28.7 1 Week - End 856 870 902 23.8 Feed intake, g/day 1-4 Weeks 4 Week~ - End 3180 3333 3222 118.7 1 Week - End 3430 3440 3630 116.2 3285 3381 3389 100.8 Gain/Feed 1-4 Weeks .273 .273 .281 .008 4 Week~ - End .247 .236 .247 .009 1 Week - End .261 .257 .266 .008 CA 022l67~ l997-09-29 W096/30405 PCT~S96103490 Table 6 The effects of active ; ;zation of finishing pigs with peptides on carcass measurements and organ weights ControlI =unized I =unized SEM
Ova/ova Peptide Cys-Peptide No. pens/pigs 5/25 5/25 5/23 Carcass weight, kg86.0 86.4 85.9 .9 Dressing percent 72.1 72.S 71.5 .3 Carcass length, cm82.6 82.7 83.5 .5 Organ weight, g Heart 397 400 415 8.4 Liver 1838 1810 1885 38.9 Kidneys 397 388 411 9.3 Spleen 166 167 183 6.9 Leaf fat 1569 1291** 1313* 73.1 Semit~n~;nosis 457 492* 467 10.0 Fat thickness, cm 1st rib 4.5 4.3 4.5 .13 Last rib 2.6 2.6 2.6 .10 Lumbar 2.0 2.0 2.3 .09 Backfat 3.0 3.0 3.1 .09 6th rib 2.4 2.3 2.3 .09 10th rib 3.0 2.9 2.9 .13 Adjusted 10th rib fat, 2.6 2.5 2.4 .1 cm Loin eye area, cm246.8 46.7 46.8 1.1 Adjusted loin eye area, 43.6 43.6 43.4 1.1 cm2 Calculated lean (33) Rg 40.6 40.7 40.9 .5 % 58.2 58.5 58.6 .7 * Significantly different than control, Pc.05 ** Significantly different than control, Pc.01 W 096/30405 PCT~US96/03~90 B;~l;ogr~hsy 1. Pell, J.M., and Bates, P.C., et al., Nutr;tion Res., Rev. 3., 163-192 (1990).
2. Abdel-Meguid, S.S., et al., Prod. Nat.
Acad. Sc;. USA, ~, 6434-6437 (1987).
3. McLaren, D.G. et al., J. Anim. Sci., 68, 640-651 (1990).
4. Campbell, R.G., et al., J. An;m. SCi., 69, 1522-1531 (1991).
5. Aston, R., et al., J. ~n~cr;
381-388 (1986).

6. Aston, R., et al., Molec~ Tmm~n~l , 143-150 (1987).

7. Holder, A.T., et al., J ~n~ncr;nn R9-R12 (1985).

8. Holder, A.T., et al., J. ~n~cr;nnl.
117, 85-90 (1988).

9. Wallis, M., et al., B;ot~hfm. Ri o~hy~.
Re8. ~mm7~n., 1~2~ 187-193 (1987).

10. Wang, B.S., et al., Molec. Tmm--n~l., 29, 313-317 ~1992).

11. Ivanyi, J., Molec. Tm,~l~nnl, 19~ 1611-1618 (1982).

12. Thomas, H.I., et al., B;o~hem. J., 243, 365-372 (1987).

13. Ma~sart, S., et al., J. ~n~:iocr; n~l ogy~
139, 383-393 (1993).

14. Pell, J.M., and Aston, R., J.
Fn~ncr;nol., 31, Rl-R4 (1991).

15. Ho, S.P., and DeGrado, W.F., J. Am.
Chem. Soc., 109, 6751 (1987).

16. Marqusee, S., and Baldwin, R.L., Pro~.
-t. Ac~. Sc;. USA, 84, 8898 (1987).

17. Jack~30n, D.Y., et al., J. Am, ~h~--.

CA 022l67~ l997-09-29 W096/30405 PCT~S96/03490 ~Q~~ , 9391 (l991).

18. Osapay, G., et al., J. Am, ~h~m. Soc., 11~, 6966 (1992).

19. garle, I.L., et al., Prod. Nat. Acad.
Sci. USA, 84, 5087 (1987).

20. Shoemaker, R.R., et al., Prod. Nat.
Acad. Sc;. USA, 82, 2439 (1985).

21. Forwood, B., et al., Prod. Nat. Acad.
Sc;. USA, 90, 838 (1993).

22. ~n~el, T.M., et al., Sc;ence, ~1, 879 (1993).

23. Benjamin, D.C., and Wigle, W.D., Tmm~lnnrhem~, 8, 1087-1097 (1971).

24. Crumpton, M.J., and Wilkinson, J.M., B;och~. J., 94, 545 (1965).

25. Geysen, H.M., et al., J. Im~u~ol.
Me~h~ds, 102, 254-274 (1987).

26. Hara, ~., et al., Bioche~mistry, 17, 550-556 (1978).

27. ~nk;3piller, M.W., and Hood, ~.E., Methods in Enzy3~olo~y, 91, 486-493 (1983).

28. Merri~ield, R.B., J. ~m . ~h~m . SOC ., 85, 2149-2154 (1963).

29. Getzoff, E.D., et al., Adv. I r~ol., 43, 1-98 (1988).

30. Chou, P.Y., and Fasman, G. D., ~31 .
Rev. B;ochem~, 47, 251-276 (1978).

31. C~ln~;n~h-3~, B.C., and Wells, J.C., Sc;~n~e, ~4~, 1081-1085 (1989).

32. Groesbeck, M.D., and Parlow, A. F., cr;n~logy, l~Q, 2582-2590 (1987).

33. Boggs, D.L., and Merkel, R.A-, ~iY~ -An;m~l ~r~R8 ~v~ll3~t; ~n ~n~ S~l ect~on Ma~3~l (1979).

34. National Pork Producers Council, Proce~3nres to ~v~ te M3rket ~ng Perform~n~e (1983).

W 096/30405 PCT~US96/03490 ~QU~-N-~ LISTING

(1) ~RN~uAT- lN~ OK~ATION:
(i) APPLICANT: Buckwalter, Brian L.
Shieh, Hong-Ming Wang, Bosco S.
(ii) TITL_ OF INv~llON: Peptides With Growth Pro ~ tion Properties (iii) NUMBER OF ~yu~. - R.C: 21 (iv) Co~K~p~ ~KN. K ~n~ReS:
(A'~ AnD~R-eSRR: American Cyanamid Company B STRBET: One Cy~ ~ Plaza ~C~ CITY: W~yne D~ STATE: New Jersey B CO~ ~Y: U.S.A.
~FJ ZIP: 07470-8426 (v) COMP~TER TR~n~T-R FORM:
(A) MBDIUM TYP_: Floppy disk (B) COMP~TER: IBM PC compatible (C) OPERATING SYSTEM: PC-DOS/MS-DOS
(D) SOFTWARE: PatentIn RelQa~Q #1.0, VQrsion #1.25 (vi) ~UKK~ APPLICATION DATA:
(A) APPLICATION N~MBER: ~S
(B) FILING DATE:
(C) CLASSIFICATION:
(viii) AllOK~._~/AG~NT lN~O~ ~TION:
(A) NAME: Gordon, Alan M.
(B) REGISTRATION N~MBER: 30,637 (C) R_~KK_N~/DOCRBT N~MBER 32,083-00 (ix) T_LECOMM~NICATION INFORMATION:
(A) TBLEPHONE: 201-831-3244 (B) TELEFAX: 201-831-3305 (2) INFORNATION FOR SBQ ID NO:l:
(i) ~yu~-N~ ~R~ CTR~ T-C TICS:
(A~ LBNGTH: 15 ~;no acids (B TYPB: amino acid (C I ST~N~ ~N KeS single (DJ TOPOLOGY: linear (ii) ~OTR~u~-~ TYPE: protein (iii) nYr~ CAL: NO
(iv) ANTI-SENSE: NO

-(xi) ~yu N~K DRSCRIPTION: SEQ ID NO:l:
Xaa Xaa LQu Xaa Xaa Ile Xaa Xaa Xaa ~eu Xaa Xaa Val Xaa Xaa CA 022l6755 l997-09-29 (2) lN~ORrATION FOR SEQ ID NO:2:
Uu-N~ C~TR~ T .CTICS:
(A' LENGTH: 17 ~;no acids (Bl TYPE: amino acid (Cl STR~N~-K.. Kes single (D TOPOLOGY: linear (ii) r ~T~T~C~T~T~ TYPE: protein (iii) ~Y~G~ CAL: NO
(i~) ANTI-SBNSE: NO

(xi) ~yl ~R DESCRIPTION: SEQ ID NO:2:
Tyr Ser Leu Asp Asp Ile Ile Arg Arg Leu Asp Asp Val Ile Arg Arg Ile (2) lN~Oh~ATION FOR SEQ ID NO:3:
(i) ~QU~N~ r~R~rTR~T,eTICS
'A) LENGTH: 17 amino acids ~B) TYPR: amino acid C) STR~ ~eS: single D) TOPOLOGY: linear (ii) MOTRC~T~ TYPE: protein (iii) nY~OLn~.lCAL: NO
(iv) ANTI-SENSE: NO

(xi) ~_yu~N.~_ DESCRIPTION: SEQ ID NO:3:
Tyr Ser Leu Asp Arg Ile Ile Arg Asp Leu A~p Arg Val Ile Arg Asp Ile (2) lN~K~ATION FOR SBQ ID NO:4:
(i) ~_QU~N~ ~T~TERISTICS:
(A) LENGTH: 17 amino acids (B) TYPE: ~no acid (C) STR~N~ NK~S: single (D) TOPOLOGY: linear (ii) M~TRC~TT~ TYPE: protein (iii) nY~O~n~llCAL: NO
(i~) ANTI-SENSE: NO

(Xi ) ~yU~N~ D_SCRIPTION: SEQ ID NO:4:
Tyr Ser Leu Arg Arg Ile Ile Arg Arg Leu Arg Arg Val Ile Arg Arg Ile (2) INFORMATION FOR SFQ ID NO:5:
( i ) ~ KQ v ~ ~R~rTR~T~Ics:
~A) LENGTH: 17 amino acids B) TYPE: amino acid C) ST~N~J~:IJNK~S single ~D) TOPOLOGY: linear (ii) NOTRC~TR TYPE: protein (iii) nYrO ~CAL: NO
(iv) ANTI-SENSF: NO

(Xi ) ~QU~N~ DESCRIPTION: SEQ ID NO:5:
Tyr Ser Leu Asp Asp Ile Ile A~p Asp Leu Asp Asp Val Ile Asp Asp Ile (2) INFORNATION FOR SEQ ID NO:6:
(i) ~Qu-~ ~ r~R~rTR~T~cTIcs:
(A) ~ENGTH: 17 A~i no acids (B) TYPE: amino acid (C) STR~N~JIC~NICCS E~ingle (D) TOPOLOGY: linear (ii) MOT~RC~TR TYPE: protein (iii) nYrO~ CAL: NO
(iv) ANTI-SENSR: NO

(xi) S~UU~N~ DESCRIPTION: SEQ ID NO:6:
Tyr Ser ~eu Asp Asp Ile Ala Arg Arg Leu Asp Asp Val Ala Arg Arg Leu ( 2 ) IN~ O~ATION FOR SEQ ID NO:7:
(i) ~yu~.~ R~rTRRTSTICS:
(A) LENGTH: 16 A~ no acids (B) TYPE: A~;no acid -CA 022l6755 l997-09-29 (C) ST~Nl ~Kl l~ S single (D) TOPOLOGY: linear (ii) MOTRC~TR TYPE: protein (iii) HYPOTHETICAL: NO
(iv) ANTI-SENSE: NO

(xi) SK~U~NCK DESCRIPTION: SEQ ID NO:7:
Tyr Ser Leu Lys Ala Ile Ala Glu Ala Leu Ly8 Ala Val Ala Glu Ala (2) INFORMATION FOR SEQ ID NO:8:
KU~ R t~T~R~t~TR~TsTIcs 'A; L~NGTH: 17 amino acids ~Bl TYPE: amino acid C~ STRAN~.~SS: single ~D TOPOLOGY: linear (ii) ~C~TR TYPE: protein (iii) HYPOTHETICAL: NO
(iv) ANTI-SENSE: NO

(xi) ~QUKW~ DESCRIPTION: SEQ ID NO:8:
Tyr Ser Leu Lys Glu Ile Glu Lys Leu Leu Lys Glu Val Leu Glu Ly~

Leu (2) lN~vK~ATION FOR SEQ ID NO:9:
(i) ~uKN~ CHARACTERISTICS:
A) LENGTH: 17 amino acids B) TYPE: amino acid C) ST~2~NIlK~ ~NlCpS single ~D) TOPOLOGY: linear (ii) I .Rc~T.R TYPE: protein (iii) HYPOTHETICAL: NO

(iv) ANTI-SENSE: NO

(xi) ~U~._K DESCRIPTION: SEQ ID NO:9:
Tyr Ser Leu Asp ABP Ile Ala Arg Arg Leu Asp Asp Val Ala Arg Arg l 5 10 15 W 096l30405 PCTAUS96/03490 Ala (2) INFORNATION FOR SFQ ID NO:10:
(i) S~ R rU~ Ku~c~lcs:
(A) LBNGTH: 16 amino acidD
(B) TYPB: Am;no acid (C) ST~~ K~Nlccs 8ingle (D) TOPOLOGY: linear (ii) - RC~-~ TYPB: protein (iii) AY~O.~lCAL: NO
(iv) ANTI-SENSE: NO

(xi) x~yu~ K L~ U~ ON: SEQ ID NO:10:
Tyr Ser ~eu Lys Ile Ile Ile Glu Ile Leu Lys Ile Val Ile Glu Ile (2) INFORMATION FOR SBQ ID NO:11:
(i) XKyuL_,_K ~U~T.cTICS
A) LFNGTH: 17 amino acids ~B) TYPB: ~mino acid C) ST~I ~KI ~ K.CS single ~D) TOPOLOGY: linear (ii) MOT~RC~R TYPE: protein (iii) ~-AL.LCAL: NO
(iv) ANTI-SFNSE: NO

(xi) ~Kyl ~ DESCRIPTION: SBQ ID NO:11:
Tyr Ser Leu Lys Glu Ile Glu Lys Leu Leu Lys Glu Val Leu Glu Lys Leu (2) INFORMATION FOR SBQ ID NO:12:
(i) ~Lyu~N~-K ~U~CTR~ T CTICS:
(A) L~NGTH: 16 amino acids (B) TYPB: amino acid (C) S'~ K~ '--KSS: single (D) TOPOLOGY: linear ~ ~ TYPB: protein (iii) AY~OlA~l~AL: NO
(i~) ~NTI-SBNSE: NO

CA 022167~ 1997-09-29 W O 96/30405 PCTrUS96/03490 (ix) FFAT~RB:
(A) NAML/KEY: Modi~ied-site (B) LOCATION: 5 (D) OTHER INFORMATION: /label= Aib /note= "Xaa at location 5 i8 Aibn (ix) FRAT~RF
(A) NAM~/RFY: Modified-site (B) LOCATION: 7 (D) OTHBR INFORMATION: /label= Aib /note= nXaa at location 7 is Aib"
(ix) F AT~RF:
(A) NAMF/R_Y: Modi~ied-site (B) LO QTION: 9 (D) OTHFR lN~OK~ATION: /label= Aib /note= "Xaa at location 9 i8 Aib"
(ix) FFATURF:
(A) NAM~/REY: Modi~ied-site (B) LO QTION: 12 (D) OTHER l~.~OKMATION: /label= Aib /note= "Xaa at location 12 is Aib"
(ix) FFAT~RF:
(A) NAM_/R_Y: Modified-site (B) LO QTION: 14 (D) OTHER INFORMATION: /label= Aib /note= "Xaa at location 14 is Aib"
(ix) FFAT~R_:
(A) NAMF/RFY: Modified-site (B) LO Q TION: 16 (D) OTHER lN~OK~ATION: /label= Aib /note= "Xaa at location 16 is Aib"

(Xi ) XLQUL_._L DESCRIPTION: SFQ ID NO:12:
Tyr Ser Leu ~ys Xaa Ile Xaa Glu Xaa Leu Lys Xaa Val Xaa Glu Xaa (2) lN~Oh~ATION FOR SFQ ID NO:13:
(i) SLYUL.._~ ~TFRISTICS:
(A' LFNGTH: 17 amino acids (B~ TYPE: ~ino acid (C. ST~N~ SS: single (D) TOPOLOGY: linear (ii) MnTRC~TR TYP_: protein (iii) HYPOTHETICAL: NO

(i~) ANTI-S_NS_: NO

(ix) FFAT~R_:
(A) NAML/R_Y: Modi4ied-site (B) ~OCATION: 3 WO 96130405 PCT/US96~03490 (D) OTHER lN~O~_TION: /label= Nle /note= "Xaa at location 3 is Nle n (xi) ~QU~N~ DESCRIPTION: SFQ ID NO:13:
~yr Ser Xaa Asp Asp Ile Ile Arg Arg Leu Asp Anp Val Ile Arg Arg Ile (2) lN~OkdATION FOR S~Q ID NO:14:
(i) ~yu~N~ CHARACT_RISTICS:
(A) ~ENGTH: 17 amino acids (B) TYPE: amino acid (C) S~R~ es: single (D) TOPOLOGY: linear (ii) MOLECULE TYPE: protein (iii) ~Y~O-~LlCAL: NO
(iv) ANTI-SENSE: NO

(iX) FEAT~RE
(A) NAME/KEY: Modi~ied-site (B) LOCATION: 10 (D) OTHER lN~O~nATION: /label= Nle /note= "Xaa at location 10 iB Nlen (Xi) ~QU~N~ DESCRIPTION: SEQ ID NO:14:
Tyr Ser Leu Asp Asp Ile Ile Arg Arg Xaa Asp Asp Val Ile Arg Arg Ile (2) INFORMATION FOR SEQ ID NO:15:
(i) ~il:-~U~NI.;15 ~7~C'TRl2T~:TICS:
A~ LENGTH: 17 ~m; no acids B TYPB: amino acid ~CJ STP~ CS: single ~D,~ TOPOLOGY: linear (ii) MOTRC~ TYPE: protein (iii) ~Y~O ~llCAL: NO
(iv) ANTI-SENSE: NO

(ix) FEATURE:
(A) NAMB/REY: -'; f; e~-site (B) LOCATION: 13 (D) OTH~R LN~O~TION: /label= Nle /note= "Xaa at location 13 is Nle n W O 96t30405 PCTrUS96103490 (Xi ) 8_yu N~_ DESCRIPTION: SEQ ID NO:15:
Tyr Ser Leu Asp Asp Ile Ile Arg Arg Leu Asp Asp Xaa Ile Arg Arg Ile (2) INFOhMATION FOR SEQ ID NO:16:
(i) S_YU_NC_ ~U~rTERISTICS:
~A) L_NGTH: 17 amino acids B) TYPE: amino acid C) ST~N~ ~K~ Jr~K! S single ,D) TOPOLOGY: linear ( ii ) -.R~T.R TYPE: protein (iii) ~lY~OIA~ NO
(iv) ANTI-SENSE: NO

(ix) FEAT~R_:
(A) NAME/REY: Modified-site (B) LOCATION: 3 (D) OTHER l~.~uK~ATION: /label= Nle /note= "Xaa at location 3 i~ Nle"
(ix) FEAT~RB:
(A) NAMB/REY: Modified-site (B) LOCATION: 10 (D) OTHER l~OhnATION: /label= Nle /note= "Xaa at location 10 i~ Nle"

(xi) ~yu~N~_ DESCRIPTION: SEQ ID NO:16:
Tyr Ser Xaa Asp Asp Ile Ile Arg Arg Xaa Asp Asp Val Ile Arg Arg l 5 10 15 Ile (2) INFORMATION FOR SEQ ID NO:17:
(i) ~_QU~N~ r~TR~TSTICS:
(A) LENGTH: 18 ~;no acids (B) TYPE: ~ino acid (C) STT~Nl~K~JNKcs single (D) TOPO~OGY: linear (ii) M~T~RC~-R TYPE: protein (iii) ~Y~O~ lCAL: NO
(iv) ANTI-SENSE: NO

(xi) SEQ~ENC_ nR~C~TPTION: SEQ ID NO:17:

W ~g6l30405 PCT~US96/03490 Cy~ Tyr Ser Leu Asp Asp Ile Ile Arg Arg L~u Asp Asp Val Ile Arg Arg Ile (2) INFORMATION FOR SEQ ID NO:18:
(i) XK5~UlsN~;ls ~T~rTERISTICS:
'A) LENGTH: 17 _mino acids B) TYPE: ~ino acid ~C) ST~ N,J~, Kqs 13ingle .D) TOPOLOGY: linear (ii) MOtRC~TR TYPE: protein (iii) ~Y~O~ CAL: NO
(iv) ANTI-SENSE: NO

(Xi) ~U~N~ DES~KI~lO_.: SEQ ID NO:18:
Xaa Xaa Xaa Xaa Xaa Leu Xaa Xaa Xaa Ile Xaa Xaa Leu Xaa Xaa Xaa Val (2) INFORMATION FOR SEQ ID NO:l9:
(i) S~UU~N~-~ CHARACTERISTICS:
(A) LENGTH: 17 amino acids (B) TYPE: ~m;no acid (C) ST~N~ ~~. K. S single (D) TOPOLOGY: linear (ii) MOT-~Cu~T~ TYPE: protQin (iii) HYPOTHETICAL: NO
(iv) ANTI-SENSE: NO

(xi) ~UuKN~K DESCRIPTION: SEQ ID NO:l9:
Xaa Xaa Ile Xaa Xaa Leu Xaa Xaa Xaa Ile Xaa Xaa Leu Xaa Xaa Xaa Val -(2) lN~OkdATION FOR SEQ ID NO:20:
(i) ~KyuL~ ~ ~TERISTICS:
~A) ~ENGTH: 17 _mino Acids B) TYPE: ~;no acid C) S~r~N~ ~K- ~ K~S single ~D) TOPOLOGY: linear CA 022l6755 1997-09-29 W 096/30405 PCT~US96/03490 (ii) ~, ~RC~T-R TYPE: protein (iii) HY~G~ lCAL: NO
(iv) ANTI-SENSE: NO

(Xi) ~U~N~ D_SCRIPTION: SEQ ID NO:20:
Tyr Ser Ile Asp A~p Leu Ile Arg Arg Ile Asp Asp Leu Ile Arg Arg Val (2) INFORMATION FOR S_Q ID NO:21:
(i) SEQ~ENC_ rU~T~rTF~TCTICS:
'A) ~ENGTH: 16 A~;no acids B) TYPE: ~mino acid C) ST~N~JK~JNK.C:S single ~D) TOPO~OGY: linear (ii) MOTKC~TTK TYPE: protein (iii) nY~ ~lCAL: NO
(i~) ANTI-SENSE: NO

(xi) ~yu~N~ DESCRIPTION: SEQ ID NO:21:
Tyr Ser Ile Asp Asp Ile Ile Arg Arg Ile Asp Asp Ile Arg Arg Ile

Claims

Claims:

1; A peptide comprising the sequence of amino acids Xaa-Xaa-Leu-Xaa-Xaa-Ile-Xaa-Xaa-Xaa-Leu-Xaa-Xaa-Val-Xaa-Xaa (SEQ ID NO:1), wherein the sequence differs from the native sequence of porcine somatotropin (pST) and wherein the peptide enhances the activity of pST and promotes growth of warm-blooded animals.

2. The peptide of Claim 1 wherein the amino acid immediately amino-terminal to the first leucine is serine.

3. The peptide of Claim 2 wherein the peptide is selected from the group consisting essentially of the peptides having the sequence depicted in SEQ ID NOS:2 through 12.

4. The peptide of Claim 1 wherein a cysteine is a dded to either or both ends of the peptide.

5. The peptide of Claim 4 wherein the peptide has the sequence depicted in SEQ ID NO:17.

6. A peptide comprising the sequence of amino acids Xaa-Xaa-Xaa-Xaa-Xaa-Leu-Xaa-Xaa-Xaa-Ile-Xaa-Xaa-Leu-Xaa-Xaa-Xaa-Val (SEQ ID NO:18) and wherein the sequence differs from the native sequence of pST.

7. The peptide of Claim 6 wherein the third residue is isoleucine, such that the peptide comprises the sequence of amino acids Xaa-Xaa-Ile-Xaa-Xaa-Leu-Xaa-Xaa-Xaa-Ile-Xaa-Xaa-Leu-Xaa-Xaa-Xaa-Val (SEQ ID NO:19) and wherein the sequence differs from the native sequence of pST.

8. The peptide of Claim 7 wherein the amino acid immediately amino-terminal to the first isoleucine is serine.

9. A composition for promoting the growth of a warm-blooded animal which comprises at least one peptide of Claims 1, 4, 5, 6, 7 or 8 together with a pharmaceutically acceptable adjuvant, diluent or carrier.

10. A method for promoting the growth of a warm-blooded animal which comprises administering to a warm-blooded animal the composition of Claim 9.