KR101985663B1 - Antimicrobial Peptides derived from swimming crab and uses thereof - Google Patents

Abstract

The present invention provides an antimicrobial peptide derived from a swimming crab having excellent antibacterial activity.

Description

Antimicrobial Peptides Derived from Crab and Uses Thereof < RTI ID = 0.0 > Antimicrobial Peptides < / RTI >

The present invention relates to an antimicrobial peptide, and more particularly, to an antimicrobial peptide derived from a crab and its use.

Antimicrobial peptides (AMP) are essentially universal as peptides and small protein groups with broad antibacterial activity against Gram-positive and Gram-negative bacteria, fungi, viruses and parasites, and all multicellular organisms, microbes, plants and animals secrete AMP Has an innate immune defense system. Endogenous AMP is produced when an infection occurs and constitutes the first line of rapid and efficient defense and is exposed to the tissues of plants and animals. The peptides have broad spectrum antimicrobial activity and can lead to restoration and adaptive immune responses in a joint response to multidrug-resistant bacteria. Typical features of AMP are net cationic charge, hydrophobicity and amphipathic. A number of studies have been conducted to develop new AMPs that enhance antimicrobial activity and reduce toxicity to eukaryotic cells, including chain length, net charge ( net charge, hydrophobicity, and structural modification. A sequence-based approach that associates the antimicrobial activity with the presence of a particular amino acid or fragment at a particular location is simple and usually requires a high level of computational techniques in a direct and efficient way among various strategies when designing new analogs of AMPs (Le et al., Sci. Rep. 5, 9761, 2015).

On the other hand, anti-lipopolysaccharide factors (ALFs) belong to an important group of antimicrobial peptides and are distributed exclusively in marine algae (chelicerate) and crustaceans. ALF shares a conserved three-dimensional structure consisting of three alpha-helical structures, typically filled against a four-stranded beta-sheet, between two conserved cysteins residues in which a group of hydrophilic and hydrophobic residues are present And a conserved LPS binding domain (LBD) formed by a disulphide bond of < RTI ID = 0.0 > Many synthetic peptides corresponding to these LBDs have antimicrobial or anti-viral activity and are used to mimic the functions of whole molecules, but some LBD peptides still do not yet exhibit significant antimicrobial activity. In addition to the amino acids of LBD, some amino acids outside the LBD have also been predicted to participate in the antimicrobial action. Some synthetic cationic LBD peptides break down bacterial cell walls and exhibit high efficiency of antimicrobial activity (Jaree et al ., Dev. Comp. Immunol . 38 (4): 554-560, 2012).

However, in the case of the prior art described above, it is difficult to expect a uniform effect due to factors such as potential toxicity without showing a sufficient antibacterial activity because the yield of peptides is not high.

Disclosure of Invention Technical Problem [8] Accordingly, the present invention has been made to solve the above-mentioned problems, and it is an object of the present invention to provide an antimicrobial peptide derived from crab having excellent antibacterial activity. However, these problems are exemplary and do not limit the scope of the present invention.

According to one aspect of the present invention, there is provided an antimicrobial peptide selected from the amino acid sequence (MARVLLRLIRL) represented by SEQ ID NO: 4 and comprising the amino acid sequence (RVLLRL) represented by SEQ ID NO: 12.

According to another aspect of the present invention, there is provided an antimicrobial composition comprising the antimicrobial peptide as an active ingredient.

According to another aspect of the present invention, there is provided a feed additive comprising the antibacterial peptide as an active ingredient.

As described above, according to one embodiment of the present invention, it is possible to realize the effect of producing crab-derived antimicrobial peptide exhibiting antibacterial activity against various strains. Of course, the scope of the present invention is not limited by these effects.

FIG. 1 shows the amino acid sequences of two maternal peptides, ALF-2N and ALF-6N, using the GOR algorithm (Ver. 4) used in the secondary structure prediction.
FIG. 2 is a diagram for predicting hydrophobic and hydrophilic regions in the secondary structure of the antimicrobial synthetic peptides ALF-2A (FRLMLRLLRW) and ALF-6A (MARVLLRLIRL) of the present invention.
FIG. 3 is a photograph showing antimicrobial activity of the antimicrobial synthetic peptides ALF-2A and ALF-6A of the present invention treated with the experimental strains E. coli, B. cereus and C. albicans
FIG. 4 is a photograph showing antimicrobial activity of the antimicrobial synthetic peptides ALF-2A and ALF-6A of the present invention against the experimental strain B. cereus after pH or heat treatment. FIG.
FIG. 5 is a photograph showing the antimicrobial activity of the antimicrobial synthetic peptides ALF-2A and ALF-6A of the present invention against the experimental strain E. coli after pH or heat treatment.
FIG. 6 is a photograph showing the antimicrobial activity of the antimicrobial synthetic peptides ALF-2A and ALF-6A of the present invention against the test strain C. albicans after pH or heat treatment.
FIG. 7 is a photograph showing antimicrobial activity of the antimicrobial synthetic peptides ALF-2A and ALF-6A of the present invention against the experimental strains E. coli, B. cereus and C. albicans after salting.
FIG. 8 is a graph showing killing kinetic studies of the antimicrobial synthetic peptides ALF-2A and ALF-6A of the present invention treated with Escherichia coli ML35p.
9 is a graph showing the results of internal membrane permeation analysis of the antimicrobial synthetic peptides ALF-2A and ALF-6A of the present invention treated with E. coli ML35 deficient in lactose-permeable enzyme.
10 is a gel photograph showing the binding ability of peptides to the DNA of the antimicrobial synthetic peptides ALF-2A and ALF-6A of the present invention.
11 is a gel photograph showing the inhibition of DNA polymerase activity of the antimicrobial synthetic peptides ALF-2A and ALF-6A of the present invention.
FIG. 12 is a photograph showing microscopic observation of changes in morphology after treating the antimicrobial synthetic peptides ALF-2A and ALF-6A of the present invention with experimental strains ( C. albicans, E. coli and S. aureus ).

Definition of Terms:

The term " antimicrobial peptide (AMP) " as used herein, is the foremost biological defense factor of the innate immune system present in all types of living organisms, from prokaryotes to mammals. Antimicrobial peptides, unlike postmortem immune responses to specific microorganisms or antigens, act largely independent of microbial species and response times are very rapid within a few hours. It is a natural product that is naturally produced to protect the host from microorganisms in a wide range of biological systems without the problem of tolerance or immune problem or rejection problem, which is different from existing antibiotics which always contain the problem of resistant bacteria. (Hancock et al., Curr Drug Targets Infect Disord. Mar ; 2 (1): 79-83, 2002). Recently, a novel AMP has been designed based on the amino acid sequence of a protein having antibacterial or bactericidal activity in genomic / transcriptome database information (He et al., Insect Biochem Mol Biol. (2): 135-46. 2007).

As used herein, the term " anti-lipopolysaccharide factors (ALFs) " belongs to the group of important antimicrobial peptides and is exclusively distributed in marine chelating agents and crustaceans. The first ALF has been identified in Limulus polyphemus and numerous ALF homologs have been reported from many crustacean species such as shrimp, lobster, lobsters, freshwater shrimp and crabs.

As used herein, the term " signal peptide " is a short (5-30 amino acid long) peptide present at the N-terminus of a number of newly synthesized proteins directed against the secretory pathway. These proteins are called endoplasmic reticulum , Golgi or endosome, or secreted from cells or inserted into most cell membranes. Antimicrobial peptides and signal peptides exhibit structural similarities. Most signal peptides start with a short positively charged stretch of amino acids (n-region) that can aid in the proper topology of the polypeptide during translocation, and the core of the signal peptide is a single alpha-helical h-region) of long hydrophobic amino acids (5 to 16 residue length).

As used herein, the term "swimming crab" is distributed throughout the marine area and lives on a sandy or sandy mud floor with a depth of 2 to 110 m. The carapace is light blue with a greenish color or dark blue, and there is a white dotted pattern on a violet background on the legs. On the south coast, objects whose entire body is purple are also common. There are three small teeth on the forehead, but the middle ones disappear from the older ones and appear to be two. Spawning season is from April to August, and it is estimated that the life span is about 3 years after going through 4 stages of Joea larvae.

DETAILED DESCRIPTION OF THE INVENTION [

According to one aspect of the present invention, there is provided an antimicrobial peptide selected from the amino acid sequence (MARVLLRLIRL) represented by SEQ ID NO: 4 and comprising the amino acid sequence (RVLLRL) represented by SEQ ID NO: 12.

In the antimicrobial peptide, the C-terminus may be amidated and may be composed of an amino acid sequence selected from the group consisting of SEQ ID NOS: 4 to 10 and 12.

According to another aspect of the present invention, there is provided an antimicrobial composition comprising the antimicrobial peptide as an active ingredient.

In the above antimicrobial composition, the Gram positive bacteria may have an antimicrobial activity against Gram-negative bacteria, Gram positive bacteria and fungi, and the Gram positive bacteria may be Bacillus cereus , Staphylococcus aureus , Streptococcus iniae , or S. mutans and the Gram negative bacteria may be Escherichia coli or Pseudomonas aeruginosa And the fungus may be Candida albicans .

According to another aspect of the present invention, there is provided a feed additive comprising the antibacterial peptide as an active ingredient.

The effective amount of the antimicrobial peptide of the present invention may vary depending on the kind of the affected part of the patient, the application site, the number of treatment, the treatment time, the formulation, the condition of the patient, The amount to be used is not particularly limited, but may be 0.01 μg / kg / day to 10 mg / kg / day. The above-mentioned daily dose may be administered once a day or two or three times a day at appropriate intervals, or intermittently administered at intervals of several days.

The antimicrobial peptide of the present invention may further contain suitable carriers, excipients and diluents which may be contained in an amount of 0.1 to 100% by weight based on the total weight of the composition and which are conventionally used in the production of pharmaceutical compositions. In addition, solid pharmaceutical preparations or liquid pharmaceutical preparations can be used for the preparation of pharmaceutical compositions. The preparation additive may be either organic or inorganic. Examples of excipients include lactose, sucrose, saccharose, glucose, cornstarch, starch, talc, sorbit, crystalline cellulose, dextrin, kaolin, calcium carbonate and silicon dioxide. Examples of the binder include polyvinyl alcohol, polyvinyl ether, ethylcellulose, methylcellulose, gum arabic, tragacanth, gelatin, shellac, hydroxypropylcellulose, hydroxypropylmethylcellulose, calcium citrate, Dextrin and pectin, and the like. Examples of the lubricant include magnesium stearate, talc, polyethylene glycol, silica, and hydrogenated vegetable oil. Any coloring agent may be used as long as it is usually allowed to be added to pharmaceuticals. These tablets and granules can be suitably coated with sugar (sugar coating), gelatin coating, and others as required. If necessary, preservatives, antioxidants and the like may be added.

The antimicrobial peptide of the present invention can be prepared in any formulations conventionally produced in the art (for example, Remington's Pharmaceutical Science (latest edition; Mack Publishing Company, Easton PA), the form of the formulation is not particularly limited. These formulations are generally known prescription Seo literature ^{[Remington's Pharmaceutical Science, 15 th} Edition, 1975, Mack Publishing Company, Easton, Pennsylvania 18042 all Agency: is described in (Chapter 87 Blaug, Seymour).

The antimicrobial peptide of the present invention can be administered orally or parenterally. Preferably, the anticancer peptide is administered by intravenous injection, subcutaneous injection, intracerebroventricular injection, intracerebrospinal fluid injection, intramuscular injection And intraperitoneal injection.

Hereinafter, the present invention will be described in more detail by way of examples. It should be understood, however, that the invention is not limited to the disclosed embodiments, but may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, Is provided to fully inform the user.

Example 1: Design and characterization of antimicrobial peptides

In order to develop the novel antimicrobial peptide (AMP) of the present invention, analogous peptides were devised from ALF (NCBI accession No. AFA42334) of crab. Specifically, the secondary structure of the peptide was compared to the ALF of the crab (Liu et al ., Fish Shellfish Immunol ., 34 (2): 463-470, 2013) using the GOR algorithm (Ver.4) (ExPASy) Respectively.

Among the ALF proteins of the crab, LBD showed a random coil and an extended strand and was found to be located at the 51-60th amino acid position. Thus, it was confirmed that ALF-2N (FRVMPRLRSW, SEQ ID NO: 1 ), And the signal peptide was located at the 1-11st amino acid position and had a random coil and alpha-helical structure, which was named ALF-6N (MARVLLRLIRL, SEQ ID NO: 2) (FIG. Based on the predicted secondary structure, an α-helix structure, which is known to be the most ideal structure for exhibiting antimicrobial activity, was adopted. Amidation and amino acid substitution at the C- ALF-2A (FRLMLRLLRW, SEQ ID NO: 3) and ALF-6A (MARVLLRLIRL, SEQ ID NO: 4), derivatives of ALF-2N and ALF-6N, respectively, were designed and their secondary structure was also analyzed by Schiffer-Edmundson (Fig. 2). The spiral wheel diagram generated in FIG. 2 was generated using EMBOSS Pepwheel (European Bioinformatics Laboratory, Cambridge, UK) (Ref). Using the ProtParam tool (ExPASy) (Ref), the predicted molecular weight, theoretical isoelectric point (pI), net charge, hydrophobicity, Bose index, instability index and aliphatic index The biochemical properties of the maternal peptide were compared.

As a result, as shown in Table 1, the ALF-2A had the same isoelectric point and net charge as the peptide ALF-2N, while the hydrophobicity and BA index were lower than that of ALF-2N. ALF-6A was found to have higher isoelectric charge and net charge than ALF-6N, the parent peptide. The peptides were synthesized by solid phase peptide synthesis method with the permission of Anygen (Gwangju, Korea).

Peptide name Sequence (SEQ ID NO) M.W. p. Net charge Hydrophobic (kcal / mol) Bose index (kcal / mol) Instability index ALF-2N FRVMPRLRSW-NH ₂ (1) 1347.65 12.3 +3 -0.41 3.15 108.6 ALF-2A FRLMLRLLRW-NH _{2 (2)} 1403.80 12.3 +3 -3.02 1.74 104.8 ALF-6N MARVSLLLIVL-NH ₂ (3) 1227.61 9.5 +1 -1.53 -1.68 12.59 ALF-6A MARVLLRLIRL-NH ₂ (4) 1353.78 12.3 +3 -0.11 1.08 37.82

Experimental Example 1: Analysis of antimicrobial activity of synthetic peptides

The present inventors analyzed the antimicrobial activity of the parent peptide (ALF-2N and ALF-6N) and derivatives (ALF-2A and ALF-6A) synthesized in Example 1 above.

The antimicrobial activity assay was carried out through ultrasensitive radial diffusion assay (Seo et al ., Biochem. Biophys. Res. Commun . 338: 1998-2004, 2005) . Bacillus cereus ATCC21772, Staphylococcus aureus ATCC6538, Streptococcus siniae FP5229, and S. mutans KCTC3065 were used as the gram-positive bacteria for the antimicrobial activity analysis, Escherichia coli KCTC1116 and Pseudomonas aeruginosa KCTC2004 were used as Gram-negative bacteria, Candida albicans KCTC7965 was used.

Specifically, the bacterial strains were cultured in brain-heart infusion medium (BHI; BD Biosciences, San Jose, CA, USA) at appropriate temperature conditions ( P. aeruginosa and S. iniae at 25 ° C and the other strains at 37 ° C) Strain C. albicans was cultured in 25 ㅀ C yeast medium. After approximately 16-18 hours of incubation, the bacteria and C. albicans suspensions were incubated with McFarland turbidity standard 0.5 (Vitek Colorimeter # 52, corresponding to ~ 10 ⁶ CFU / mL for C. albicans and ~ 10 ⁸ CFU / mL for bacteria -1210; Hach, Loveland, CO, USA). A 500-mL aliquot of the diluted bacterial or C. albicans suspension was diluted with 10% Tritic Soy Broth (TSB) or 0.03% Sabouraud Dextrose Broth (SDB) and 1% type I low-EEO agarose 9.5 mL of underlay gel containing 5x10 ⁶ CFU / mL or 5x10 ⁴ CFU / mL in mM PBS (pH 6.6) was added. The purified peptide was then serially diluted twice in 5 [mu] L of acidified water (0.01% HAc) and each dilution was added to a 2.5 mm diameter well made in a 1 mm thick underlay gel. After incubation for 3 hours at 25 캜 ( P. aeruginosa , S. iniae and C. albicans ) or 37 캜 (other strains), the bacterial or yeast suspension was resuspended in 10 mL of 10% PBS (pH 6.6) and 1% The rose was overlayed on the underlay gel with a 10 mL double strength overlay gel containing 6% BHI or 6% YM. The plate was then incubated for an additional 18-24 hours, then the diameter of the clearing zone was measured and the diameter of the wells was subtracted and the diameter of the clear zone was expressed in units (0.1 mm = 1 U). The minimum effective concentration (MEC, μg / mL) of the synthetic peptides was calculated as the x-intercept of the plot of the units described above for the log10 of peptide concentration and the antibacterial assays were averaged over three runs.

As a result, the antimicrobial activity of the parent peptide, ALF-2N and ALF-6N, was not confirmed (data not shown), but excellent antimicrobial activity was observed in the respective derivatives ALF-2A and ALF-6A. ALF-2A was detected at 5 ㎍ / mL for Gram-positive B. cereus , S. aureus , and S. iniae (MECs 1.51-1.93 ㎍ / mL) and Gram-negative P. aeruginosa and E. coli (MECs 1.87-1.98) , And ALF-6A showed the highest antimicrobial activity at the peptide concentration of 5 ㎍ / mL, while the gram-negative B. cereus, S. aureus , and S. iniae (MECs 1.49-2.3 ㎍ / mL) - Antimicrobial activity of minimal efficacy against P. aeruginosa and E. coli (MECs 1.72-1.19 ㎍ / mL). Therefore, the minimum effect concentrations of ALF-2A and ALF-6A on C. albicans were 2.11 and 1.95 ㎍ / mL, respectively. The minimum effect concentration (MECs) results of the antimicrobial peptides synthesized in the present invention are shown in Table 2 below.

microbe
Minimum effect concentration (μg / mL) ALF-2A ALF-6A Gram-positive bacteria
B. cereus ATCC 21772 1.51 1.88 S. aureus RM4220 1.87 1.79 S. iniae FP5229 1.93 2.3 S. mutans KCTC3065 1.73 1.49 Gram-negative bacteria
P. aeruginosa KCTC2004 1.98 1.72 E. coli KCTC1116 1.87 1.79 leaven C. albicans KCTC7965 2.11 1.95

Example 2: Preparation of miniaturized ALF peptide derivatives

Since both of the two antimicrobial peptides (ALF-2A and ALF-6A) synthesized in Example 1 showed strong antimicrobial activity over a wide range, the instability index of ALF-2A was higher than that of ALF-6A. -6A was selected as a more potent antimicrobial agent and the minimum active site of ALF-6A was determined. Thus, the present inventors devised and synthesized deletion mutants in which 1 to 4 amino acids at the N-terminal and / or C-terminal of ALF-6A have been deleted (see Table 3). The sequence, predicted molecular weight, predicted isoelectric point, net charge, hydrophobicity, instability index, and bow index of the deletion mutants are shown in Table 3 below.

Meanwhile, the synthesis of the peptides of the present invention including ALF-2A and ALF-6A was performed using a solid-phase peptide synthesis method of Anygen Co., Ltd. (Gwangju, Korea). The peptides were dissolved in acidified distilled water and stored at -20 < 0 > C until use.

SEQ ID NO: Peptides order Molecular Weight p. Net charge Hydrophobic (kcal / mol) Instability index Bose index (kcal / mol) 4 ALF-6A MARVLLRLIRL (-NH ₂₎ 1353.79 12.3 +3 -0.11 37.82 1.08 5 ALF-6A1 -ARVLLRLIRL (-NH ₂₎ 1222.59 12.3 +3 0.12 28.26 1.43 6 ALF-6A2 MARVLLRLIR - (- NH ₂₎ 1240.62 12.3 +3 0.45 40.60 1.68 7 ALF-6A3 -ARVLLRLIR - (- NH ₂₎ 1109.43 12.3 +3 0.68 30.29 2.13 8 ALF-6A4 --RVLLRLIR - (- NH ₂₎ 1038.35 12.3 +3 0.51 32.83 2.63 9 ALF-6A5 -ARVLLRLI - (- NH ₂₎ 953.24 12.0 +2 -0.31 32.83 0.53 10 ALF-6A6 --RVLLRLI - (- NH ₂₎ 882.16 12.0 +2 -0.3 36.09 0.87 11 ALF-6A7 --- VLLRLI - (- NH ₂₎ 725.97 9.72 +1 -1.11 40.43 -1.46 12 ALF-6A8 --RVLLRL --- (- NH ₂₎ 769.004 12.0 +2 0.01 40.43 1.84 13 ALF-6A9 --- VLLRL --- (- NH ₂₎ 612.816 9.72 +1 -0.8 46.52 -0.77 14 ALF-6A10 --RVLLR ---- (- NH ₂₎ 655.844 12.0 +2 0.57 46.52 3.19

Experimental Example 2: Antimicrobial activity analysis of deletion mutants

The antimicrobial activity of the deletion mutants of ALF-6A prepared in Example 2 was analyzed in the same manner as in Experimental Example 1 (FIG. 3).

As a result, as shown in Fig. 3, it was confirmed that the minimum unit of antibacterial activity was a hexapeptide (RVLLRL, SEQ ID NO: 12) from the third amino acid (arginine) to the eighth amino acid (leucine) of ALF-6A. In particular, when the third amino acid arginine or the eighth amino acid leucine is removed, the antimicrobial activity is completely lost, and the hexapeptide has an antibacterial activity comparable to that of ALF-6A. However, the antimicrobial activity against B. cereus , a Gram-positive bacterium, was found to decrease as the length of the peptide decreased.

Experimental Example 3: Effect of pH, Temperature and Salinity on Antimicrobial Activity

Effect of addition of NaCl (0.5%, 1.0%, 1.5%, and 2.0%), pH (5.0, 6.0, and 7.0) and temperature (80 ° C) in the activity of the antimicrobial active peptides ALF-2A and ALF- Was calculated using URDA. The peptide (5 / / mL) was dissolved in 50 mM sodium acetate buffer (pH 5.0 and pH 6.0) or Tris-HCl buffer (pH 7.0) to investigate the thermal stability at different pH, After incubation for 6 hours at room temperature, they were used for URDA against B. cereus , E. coli , and C. albicans . In order to examine the salinity effect, underlay medium was added with NaCl of the desired concentration (0.5%, 1.0%, 1.5%, and 2.0%), each microorganism was added to the medium, the plate was cultured for 24 hours , And zones of inhibition were measured.

As a result, it was confirmed that the antimicrobial activity of the synthesized peptide was not greatly changed by pH or heat treatment as proved by the strong antibacterial activity against the test strains (FIGS. 4 to 6) and was influenced by the sodium chloride concentration, Antibacterial activity against C. albicans ALF-2A and ALF-6A completely disappeared in 1.5% and 1.0% sodium chloride in medium, respectively (FIG. 7)

Experimental Example 4: Killing kinetic study

In order to evaluate the inhibition mode of the ALF analogs of the present invention, death studies were performed on E. coli ML35p at five times the MECs and MECs.

Specifically, E. coli ML35p was cultured overnight and then diluted in TBS to a cell concentration of 10 ⁶ CFU / mL. One mL of each suspension was exposed to each of the ALF analogs and the control group, and incubated overnight at 37 ° C. The colonies obtained after the counting were counted. The killing rate was then calculated as the percentage of live bacteria at a given time following addition of the ALF peptide analogue compared to the number of bacteria present prior to addition of the ALF peptide analog. Each bacterial control culture was cultured in the absence of ALF peptide analogs, analyzed at the time points according to the analysis time of the detached cultures, and the mortality analysis was performed three times and the average value of the results was obtained.

As a result, the antimicrobial active peptide analogs (ALF-2A and ALF-6A) and the control picidin 1 of the present invention were able to express E.coli ML35p very rapidly within 5 min in 5 x MEC and within 10 min in 1 x MEC (Fig. 8).

Experimental Example 5: Internal membrane permeability analysis

To confirm the bacterial inner membrane permeability of the antimicrobial active peptide analogues (ALF-2A and ALF-6A) of the present invention, o-nitrophenyl-β-D-galactoside (ONPG) and total nucleotide leakage E. coli ). Specifically, it was determined by measuring the β-galactosidase activity of E. coli ML35p, a lactose permease-deficient strain, using ONPG as a chromogenic substrate. Briefly, fresh Lauri-Bertanni (LB) containing 1 mM IPTG was inoculated to induce the expression of β-galactosidase in E. coli ML35p overnight culture, and cultured at 0, 10, 20, 30, 40 , 50, and 60 minutes), and ONPG was added to a final concentration of 0.4 mM and incubated at 37 ° C for 10 minutes. The ONP produced by the cleavage of ONPG by β-galactosidase was detected as A405 value by spectrophotometer.

As a result, a sharp increase in the A ₄₀₅ value (? -Galactosidase activity) in the supernatant was observed at 0 to 60 min after exposure to the antimicrobial active peptide analogs (ALF-2A and ALF-6A) Activity was higher than carb-ALF-6 (FIG. 9).

Experimental Example 6: DNA Binding Assay

DNA binding assays for the antimicrobial active peptides (ALF-2A and ALF-6A) of the present invention were performed to evaluate inhibition of the rate of migration of DNA bands through agarose gels. First, a commercially available molecular weight marker, λ- Hind III digested DNA (50 ng) (Roche, Basel, Switzerland) was mixed with various amounts of peptides (0, 0.156, 0.313, 0.625 and 1.25 μg) in 0.01% acetic acid The mixture was incubated at room temperature for 5 minutes, and then electrophoresed on 1.0% agarose gel containing 0.5 μg / mL of ethidium bromide (EtBr).

As a result, in electrophoretic migration analysis (EMSA), the electrophoretic mobility of DNA was almost completely inhibited by ALF-2A and ALF-6A at 1.25 μg compared to non-complex DNA (FIG. 10).

Experimental Example 7: DNA Polymerase Inhibition Analysis

DNA polymerase inhibition assays were performed to determine whether the antimicrobial active peptides (ALF-2A and ALF-6A) of the present invention inhibited DNA polymerase activity. Specifically, ALF-2A and ALF-6A were dissolved in 0.01% acetic acid at a concentration of 1000 μl / ml and various concentrations of ALF-2A or ALF-6A (2.5, 1.25, 0.625, 0.313 [mu] g / mL) was added to each reaction mixture. Thereafter, E. coli genomic DNA (100 ng) was used as a template for PCR amplification using 16S-F1 (SEQ ID NO: 15) and 16S-R3 (SEQ ID NO: 16) primer sets. The PCR reaction conditions were 30 cycles at 95 ° C for 30 seconds, 55 ° C for 30 seconds and 72 ° C for 1 minute, and the other predicted reaction amplifications were about 1.5 kb in length. All reaction products were EtBr Lt; RTI ID = 0.0 > 1.0% agarose gel. ≪ / RTI >

As a result, ALF-2A showed complete inhibitory activity at all experimental concentrations (0.313-2.5 ㎍), while ALF-6A showed a low inhibitory activity at 1.25 비교 compared to ALF-2A (FIG. 11). Information on the primers used in the PCR amplification is shown in Table 4 below.

primer The nucleic acid sequence (5 '-> 3') SEQ ID NO: 16S-F1 CTCCTACGGGAGGCAGCAG 15 16S-R3 CCAGGGTATCTAATCCTG 16

Experimental Example 9: Scanning Electron Microscope (SEM)

Microbial morphology of the antimicrobial active peptides (ALF-2A and ALF-6A) of the present invention was observed under a microscope. Specifically, for the microscopic observation, the form of C. albicans was observed by SEM after treatment with ALF-6A, and a medium-logarithmic phase culture of C. albicans was prepared. Then, 495 μl of fresh filtrate was added to PBS buffer Resurrection. Subsequently, C. albicans was mixed with 5 μg / ml of ALF-6A for 2 hours and collected immediately and untreated cells were used as controls. The collected cells were fixed overnight in 2.5% (V / V) glutaraldehyde in 0.1 M phosphate buffer (pH 7.4) and washed three times with 0.1 M phosphate buffer (pH 7.4) , 50, 70, 90, 95, and 100%). Subsequently, the critical point was dried and placed on 1 cm stubs, platinum-coated using a sputter coater (Q150T, Quorum) and SE2 mode (ETH = 5 kV).

As a result, shrinkage was observed, which could be caused by leakage of cytoplasmic content in microorganisms treated with ALF-2A or ALF-6A as compared with the control (Fig. 12).

In conclusion, the antimicrobial active peptide analogs (ALF-2A and ALF-6A) derived from the swimming crab antiparasitic polysaccharide factor (ALFs) of the present invention are stable to pH or heat treatment and are excellent for Gram- It is considered that it can be used as a candidate substance for the development of alternative antibiotic substitute which can replace the existing antibiotic and the development of anti-inflammatory drug.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed embodiments, but, on the contrary, is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims. Accordingly, the true scope of the present invention should be determined by the technical idea of the appended claims.

<110> Republic of Korea represented by National Fisheries Research & Development Institute <120> Antimicrobial peptides derived from swimming crab and uses          the <130> PD17-5516 <160> 16 <170> Kopatentin 2.0 <210> 1 <211> 10 <212> PRT <213> Artificial Sequence <220> <223> ALF-2N <400> 1 Phe Arg Val Met Pro Arg Leu Arg Ser Trp   1 5 10 <210> 2 <211> 10 <212> PRT <213> Artificial Sequence <220> <223> ALF-2A <400> 2 Phe Arg Leu Met Leu Arg Leu Leu Arg Trp   1 5 10 <210> 3 <211> 11 <212> PRT <213> Artificial Sequence <220> <223> ALF-6N <400> 3 Met Ala Arg Val Ser Leu Leu Leu Ile Val Leu   1 5 10 <210> 4 <211> 11 <212> PRT <213> Artificial Sequence <220> <223> ALF-6A <400> 4 Met Ala Arg Val Leu Leu Arg Leu Ile Arg Leu   1 5 10 <210> 5 <211> 10 <212> PRT <213> Artificial Sequence <220> <223> ALF-6A1 <400> 5 Ala Arg Val Leu Leu Arg Leu Ile Arg Leu   1 5 10 <210> 6 <211> 10 <212> PRT <213> Artificial Sequence <220> <223> ALF-6A2 <400> 6 Met Ala Arg Val Leu Leu Arg Leu Ile Arg   1 5 10 <210> 7 <211> 9 <212> PRT <213> Artificial Sequence <220> <223> ALF-6A3 <400> 7 Ala Arg Val Leu Leu Arg Leu Ile Arg   1 5 <210> 8 <211> 8 <212> PRT <213> Artificial Sequence <220> <223> ALF-6A4 <400> 8 Arg Val Leu Leu Arg Leu Ile Arg   1 5 <210> 9 <211> 8 <212> PRT <213> Artificial Sequence <220> <223> ALF-6A5 <400> 9 Ala Arg Val Leu Leu Arg Leu Ile   1 5 <210> 10 <211> 7 <212> PRT <213> Artificial Sequence <220> <223> ALF-6A6 <400> 10 Arg Val Leu Leu   1 5 <210> 11 <211> 6 <212> PRT <213> Artificial Sequence <220> <223> ALF-6A7 <400> 11 Val Leu Leu   1 5 <210> 12 <211> 6 <212> PRT <213> Artificial Sequence <220> <223> ALF-6A8 <400> 12 Arg Val Leu Leu Arg Leu   1 5 <210> 13 <211> 5 <212> PRT <213> Artificial Sequence <220> <223> ALF-6A9 <400> 13 Val Leu Leu Arg Leu   1 5 <210> 14 <211> 5 <212> PRT <213> Artificial Sequence <220> <223> ALF-6A10 <400> 14 Arg Val Leu Leu Arg   1 5 <210> 15 <211> 19 <212> DNA <213> Artificial Sequence <220> <223> 16S-F1 <400> 15 ctcctacggg aggcagcag 19 <210> 16 <211> 18 <212> DNA <213> Artificial Sequence <220> <223> 16S-R3 <400> 16 ccagggtatc taatcctg 18

Claims (9)

An antimicrobial peptide comprising the amino acid sequence (RVLLRL) selected from the amino acid sequence (MARVLLRLIRL) shown in SEQ ID NO: 4 and represented by SEQ ID NO: 12. The method according to claim 1,
An antimicrobial peptide wherein the C-terminus is amidated. The method according to claim 1,
An antimicrobial peptide consisting of an amino acid sequence selected from the group consisting of SEQ ID NOS: 4 to 10 and 12. An antimicrobial composition comprising the antimicrobial peptide of any one of claims 1 to 3 as an active ingredient. 5. The method of claim 4,
An antimicrobial composition having antimicrobial activity against Gram-negative bacteria, Gram-positive bacteria or fungi. 6. The method of claim 5,
Wherein said gram-positive bacteria are Bacillus cereus , Staphylococcus aureus , Streptococcus iniae , or S. mutans . 6. The method of claim 5,
Wherein the gram-negative bacterium is Escherichia coli or Pseudomonas aeruginosa . 6. The method of claim 5,
Wherein said fungus is Candida albicans . A feed additive comprising the antimicrobial peptide of any one of claims 1 to 3 as an active ingredient.

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