• 대한의생명과학회지
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• 제7권3호
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• pp.103-110
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• 2001

$\alpha$-Fetoprotein(AFP) is a good marker for the detection of several diseases such as hepatocellular carcinoma, gonadal germ cell tumor, gastric tumor, and Down's syndrome. In this study, we developed ELISA, using synthetic peptides corresponding to the epitopes of AFP. Five kinds of peptides were synthesized from AFP to produce antibodies in rats that recognize AFP in human plasma as well as amniotic fluid and do not cross-react with serum albumin. All five kinds of antibodies showed good reactivities with their peptide-keyhole limpet hemocyanin conjugates. Anti-synthetic peptide 1 (R-N-E-Y-G-I-A-S-I-L, 4-13) antibody, in particular, reacted well with AEP as well as synthetic peptide 1-KLH but not with human serum albumin. The binding affinity(Kd) was 2.7$\times$10$^{-9}$M for peptide 1 and 6.8$\times$10$^{-8}$M for AEP. The range for measurement of AFP was 10~1,000 ng/ml. The within-assay and between-assay coefficients of variance(CV) were 4.83% and 10.97%, respectively. In a sample of 31 sera and 33 amniotic fluids, there was a good correlation between AFP values determined in this assay and those in a commercial kit. These results indicate that the antibodies against synthetic peptides corresponding to the epitopes of AFP are highly specific to APP and synthetic peptide-based ELISA would be useful for the measurement of human AFP.

• Journal of Periodontal and Implant Science
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• 제40권1호
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• pp.11-18
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• 2010

Purpose: Significant interest has emerged in the design of cell scaffolds that incorporate peptide sequences that correspond to known signaling domains in extracellular matrix and bone morphogenetic protein. The purpose of this study was to evaluate the bone regenerative effects of the synthetic peptide in a critical-size rat calvarial defect model. Methods: Eight millimeter diameter standardized, circular, transosseus defects created on the cranium of forty rats were implanted with synthetic peptide, collagen, or both synthetic peptide and collagen. No material was was implanted the control group. The healing of each group was evaluated histologically and histomorphometrically after 2- and 8-week healing intervals. Results: Surgical implantation of the synthetic peptide and collagen resulted in enhanced local bone formation at both 2 and 8 weeks compared to the control group. When the experimental groups were compared to each other, they showed a similar pattern of bone formation. The defect closure and new bone area were significantly different in synthetic peptide and collagen group at 8 weeks. Conclusions: Concerning the advantages of biomaterials, synthetic peptide can be an effective biomaterial for damaged periodontal regeneration.

• 대한수의학회지
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• 제25권1호
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• pp.7-17
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• 1985

Many investigators have been pursuing various attempts so far to produce hepatitis B surface antigen(HBsAg) vaccines using the techniques such as isolation from plasma of chronic HBsAg carrier, recombinant DNA technique or preparation of synthetic peptides specific for immunogenic determinants. Hepatitis B virus can not grow on any cell lines by the tissue culture technique at the present time. The plasma of chronic HBsAg carrier is expensive and its source is limited. The HBsAg from the recombinant DNA technique gave still very low yield. Another approach, therefore, has been initiated to develop a synthetic hepatitis B virus vaccine. The possible use of several distinct synthetic vaccines in prophylaxis can be facilitated by availability of full synthetic immunogens. Peptides synthesized for potential application as antiviral vaccines have been mostly tested in the form of conjugates with carrier proteins, although the free synthetic peptide can be immunogenic. To understand basic knowledges on the antigenicity and immunogenicity of a synthetic peptide specific for major immunogenic determinant of HBsAg, a nonapeptide, $H_2N^{139}Cys-Thr-Lys-Pro-Thr-Asp-Gly-^{146}Asn-Aba$ COOH, which corresponds to HBsAg amino acid residues 139 to 147, was synthesized by the Merrifield's solid-phase method with a slight modification. The antigenicity and immunogenicity of this specific synthetic peptide were examined comparing with purified plasma-derived natural HBsAg. The results obtained are as follows; 1. The peptide synthesized showed the identical amino acid composition to the theoretical value. The degree of purification and molecular weight were acertained by methods of high performance liquid chromatography and mass spectrometry. 2. Using m-maleimidobenzoyl-N-hydroxysuccinimide ester as a conjugating agent, the synthetic peptide was conjugated to rabbit albumin and ${\gamma}$-globulin, tetanus and diphtheria toxoids, and keyhole limpet hemocyanin. Their conjugation yields were 8.3, 9.5, 15.8, 13.5, and 11.2%, respectively. 3. The natural HBsAg was purified from plasma of chronic HBsAg carrier. By the electron microscopic observation of the purified natural HBsAg preparation, no Dane particles were observed and the preparation showed negative DNA polymerase activity. 4. Antigenicity of the synthetic peptide and the plasma-derived natural HBsAg was determined by competition radioimmunoassay using $^{125}I$-natural HBsAg. Their 50% inhibitions appeared as $90{\mu}g/ml$ and $0.12{\mu}g/ml$ for the synthetic peptide and the natural HBsAg, respectively. This indicates that the former was about 750-fold less antigenic than the latter. 5. Immunogenicity of the synthetic peptide was determined by administering the peptide-carrier conjugates into rabbits with and without Freund's complete adjuvant. Regardless the carrier proteins and adjuvant, positive immune responses to the synthetic peptide were observed. The higher antibody titers, however, were shown in the groups administered with Freund's complete adjuvant. 6. Immunizing dose 50% in mice of the various peptide-carrier conjugates was 5.47, 6.00, 65.16, 31.25 and $13.03{\mu}g/dose$ for rabbit albumin and ${\gamma}$-globulin, tetanus and diphtheria toxoids, and keyhole limpet hemocyanin, respectively, while the natural HBsAg showed $0.65{\mu}g/dose$. 7. It was postulated that homologous proteins prefer to heterologous ones as the carriers.

• 한국수산과학회지
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• 제45권2호
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• pp.114-121
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• 2012

A novel neuropeptide was isolated from the skin of the snakehead Channa argus using the dorsal retractor muscle (DRM) of a starfish Asterina pectinifera as a bioassay system. The amino acid sequence of the purified peptide was analyzed using automated sequencing and MALDI-TOF mass spectrophotometry. The primary structure of the purified peptide was determined to be Pro-Ala-Leu-Ala-Leu. To investigate the complete primary structure of this peptide, Pro- Ala-Leu-Ala-Leu-OH and Pro-Ala-Leu-Ala-Leu-NH2 were synthesized. The chemical and pharmacological properties of the synthetic peptides were compared with those of the native peptide. Both the native peptide and synthetic Pro-Ala- Leu-Ala-Leu-OH had identical behaviors on the reverse-phase and cation-exchange HPLC chromatograms. Synthetic Pro-Ala-Leu-Ala-Leu-OH showed contractile activity on the DRM, and the threshold concentration of this peptide was approximately $10^{-8}$ M. The maximal contractile effect ($E_{max}$) of this peptide was $294{\pm}45.4$% at $10^{-5}$ M.

• Journal of Microbiology and Biotechnology
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• 제7권1호
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• pp.49-51
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• 1997

In order to obtain a hybrid synthetic peptide with a more potent antifungal activity than magainin-2 but without hemolytic activity, four hybrid peptides were designed from the sequences of magainin 2 and cecropin A and their antifungal activities against Trichosporon beigelii were investigated. The result showed that analogue 2 and 4 exhibited better antifungal activity against T. beigelii than magainin-2 but no hemolytic activities. The peptides, therefore, could be used as models for the development of potent antifungal peptides.

• Journal of Microbiology and Biotechnology
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• 제22권2호
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• pp.264-269
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• 2012

Recently, we reported that the synthetic Coprisin analog peptide 9-mer dimer CopA3 (consisted of all-L amino acid sequence) was designed based on a defensin-like peptide, Coprisin isolated from Copris tripartitus. The 9-mer dimer CopA3 (L-CopA3) had antibacterial activity and induced apoptosis in human leukemia cells via a caspase-independent pathway. In this study, all of amino acid sequences of L-CopA3 were modified to all D-form amino acids (DCopA3) to develop a more effective antimicrobial peptide. We investigated whether D-CopA3 had antimicrobial activities against pathogenic microorganisms and pro-apoptotic effects in human leukemia cells (U937, Jurkat, and AML-2). The synthetic peptide D-CopA3 had antimicrobial activities against various pathogenic bacteria and yeast fungus with MIC values in the 4~64 ${\mu}M$ range. Moreover, D-CopA3 caused cell growth inhibition, and increased the chromosomal DNA fragmentation and the expression of inflammatory cytokines, TNF-${\alpha}$ and IL1-${\beta}$, transcripts in human leukemia cells. The all-D amino acid peptide DCopA3 proved as effective as the L-CopA3 reported previously. These results provide the basis for developing D-CopA3 as a new antibiotic peptide.

• Applied Biological Chemistry
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• 제49권3호
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• pp.196-201
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• 2006

Vitellogenin은 어류의 난황 단백질의 전구체 물질로서 암컷 혈청에서 발견되는 단백질이며, 외부에서 에스트로겐이나 내분비계장애물질에 노출된 경우에는 수컷이나 미성숙한 암컷에서도 이의 합성이 촉진되는 것으로 보고되었다. 따라서 수컷에서 유도되는 vitellogenin은 외인성 에스트로겐 물질에 노출되었음을 암시하는 중요한 지표로 인정되고 있다. Vitellogenin에 대한 항체를 생산하기 위하여 잉어의 vitellogenin 서열 중의 일부분에 대한 peptide를 합성한 후 그 합성 peptide에 대한 항체를 제작하였다. 그리고 $17{\beta}$-estradiol을 주입한 잉어의 혈청에서 DE-52 이온 교환 크로마토그래피를 사용하여 vitellogenin을 정제한 후 이에 대한 항체를 제작하였다. 본 연구에서는 상기의 합성 vitellogenin peptide에 대하여 제작한 다클론 항체와 vitellogenin 단백질에 대한 다클론 항체가 추후 에스트로겐의 지표로 사용될 수 있는 지를 조사하고자 항체의 반응성을 조사하였다. 정제하여 얻은 vitellogenin에 대한 다클론 항체는 Western blotting 시 $17{\beta}$-estradiol을 주입한 잉어의 혈청과 암컷 잉어의 혈청에 있는 vitellogenin과 반응한 반면에 vitellogenin peptide에 대한 다클론 항체는 이들과 반응하지 않았다. 이는 공유결합적으로 많은 변형이 일어난 vitellogenin 단백질은 vitellogenin 합성 펩타이드에 대한 항체로는 검출되지 않음을 나타낸다.

• Biomolecules & Therapeutics
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• 제2권4호
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• pp.303-309
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• 1994

The analysis of membrane receptors for hormones and neurotransmitters has progressed considerably by pharmacological and biochemical means and more recently through the use of specific antibodies. Two kinds of antibodies could be produced, one is from synthetic peptides and the other from proteins such as purified receptor. Anti-peptide antibodies gave some advantages; epitope is evident and also receptor purification in quantity is not prerequisite. It can be also applied to the study of receptor structure-activity relationship. The purpose of the present study was 1) to produce and characterize a polyclonal antibody against a synthetic $\beta$2-adrenergic receptor peptide(Phe-Gly-Asn-Phe-Trp-Cys-Phe-Trp-Thr-Ser-Ile-Asp-Val-Leu) and 2) to determine the effects of this antibody on the $\beta$-adrenergic receptor ligand interaction. The peptide sequence contains an amino acid residue such as Asp-113 which was identified as one of important component for receptor-ligand interaction in site-directed mutagenesis studies. Production of antibody was performed by immunization of rabbits through popliteal lymph node with the peptide coupled with Keyhole Limpet Hemocyanin (KLH). The titer of antibody against this peptide was 1 : 1000. The anti-peptide antibody was able to detect a 67 kDa protein band in western blot corresponding to the molecular weight of the $\beta$-adrenergic receptor in partially purified receptor fraction derived from guinea pig lung. The antisera inhibited the specific binding of [$^3$H]dihydroalprenolol to $\beta$-adrenergic receptor in a concentration-dependent manner. The results from this study suggest that the peptide sequence selected in the present study is important for the receptor ligand interaction.

• 한국수산과학회지
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• 제45권4호
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• pp.358-366
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• 2012

A novel neuropeptide was isolated from the skin of the conger eel Conger myriaster using hagfish Eptatretus burgeri intestine as a bioassay system. The sequence of the purified peptide was analyzed using automated amino acid sequencing and MALDI-TOF mass spectrophotometry. The molecular ion peak in the MALDI-TOF mass spectrum of the peptide was at m/z 962.89 $(M+H)^+$. The sequence of the peptide was determined to be L-P-M-L-E-T-Q-M, and was tentatively named comyrin. To investigate the complete primary structure of comyrin, comyrin-OH and comyrin-$NH_2$ were synthesized and the chemical and pharmacological properties of the synthetic peptides were compared with those of the native peptide. However, the elution time of synthetic peptides did not match that of the native peptide on the reverse-phase HPLC chromatogram. In addition, the synthetic peptides did not cause contractile activity in the intestinal smooth muscle of the hagfish. Based on these results, one possible reason for this disagreement may be the presence of a D-amino acid in comyrin.

• Bulletin of the Korean Chemical Society
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• 제31권1호
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• pp.202-204
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• 2010