• 통합자연과학논문집
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• 제10권3호
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• pp.125-130
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• 2017

Glucagon like pepide-2, one of the GLPs, is involved in various metabolic functions in the gastrointestinal tract. It plays a major role in the regulation of mucosal epithelium and the intestinal crypt cell proliferation. Because of their therapeutic importance towards the diseases in the gastrointestinal tract, it becomes necessary to study their interaction with its receptor, GLP-2R. In this study, we have developed protein-protein docking complexes of GLP-2 - GLP-2 receptor. Homology models of GLP-2 are developed, and a reliable model out of the predicted models was selected after model validation. The model was bound with the receptor, to study the important interactions of the complex. This study could be useful in developing novel and potent drugs for the diseases related with GLP-2.

• 통합자연과학논문집
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• 제11권1호
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• pp.9-13
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• 2018

KiSS1-derived peptide receptor, a GPCR protein, binds with the hormone Kisspeptin plays a major role in the neuroendocrine regulation of reproduction. It is important in the onset of puberty and triggers the release of gonadotrophin-releasing hormone. It is a potential drug target for the disorders related to GnRH, hence, analysing the structural features of the receptor becomes important. The three dimensional of the receptor modelled in a previous study was utilised. In this study, we have analysed the protein - protein interaction of the receptor with Kisspeptin 10 and 15. The study revealed the important residues which are involved in the interaction. The result of this study could be helpful in understanding the mechanism of Kiss1 receptor activation and the pathophysiology of the disorders related to the receptor.

• Mass Spectrometry Letters
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• 제9권1호
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• pp.17-23
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• 2018

Studies on the interactions of amyloidogenic proteins with trace metals, such as copper, have indicated that the metal ions perform a critical function in the early oligomerization process. Herein, we investigate the effects of Cu(II) ions on the active sequence regions of amyloidogenic proteins using electrospray ionization mass spectrometry (ESI-MS) and collision induced dissociation tandem MS (CID-MS/MS). We chose three amyloidogenic peptides NNQQNY, LYQLEN, and VQIVYK from yeast prion like protein Sup35, insulin chain A, and tau protein, respectively. [Cu-peptide] complexes for all three peptides were observed in the mass spectra. The mass spectra also show that increasing Cu(II) concentrations decrease the population of existing peptide oligomers. The tandem mass spectrum of NNQQNY shows preferential binding for the N-terminal region. All three peptides are likely to appear to be in a Cu-monomer-monomer (Cu-M-M) structure instead of a monomer-Cu-monomer (M-Cu-M) structure.

• 한국광학회지
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• 제28권1호
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• pp.9-15
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• 2017

실리콘 기판으로 만든 바이오센서에서 펩타이드-항체의 접합 동특성을 회전 타원분광계로 정밀하게 측정하고 분석하였다. 극도로 낮은 몰농도의 펩타이드를 측정할 때, 시료가 놓이는 바이오센서의 표면의 불완전한 편평도와 완충용액 굴절률 변화로 인한 측정오차를 줄이기 위하여 금속박막의 유리 프리즘 대신에 실리콘 기판 위에 덱스트란 SAM을 직접 적층하여 바이오센서를 만들었다. $100{\mu}l/min$의 완충용액 주입속도에서 바이오센서에 올려진 항체 및 펩타이드의 접합특성을 각각 측정하였다. 리터당 5 ng의 낮은 항체농도에서도 항체-덱스트란 SAM 사이의 동특성을 쉽게 측정할 수 있었다. 또한 100 nM까지의 펩타이드에 대한 미세한 흡착 및 해리 특성을 정밀하게 측정할 수 있었으며, 접합 동특성 식에 이 실험결과를 피팅하여 흡착계수와 해리계수를 구할 수 있었다. 이 결과로부터 펩타이드의 평형상태의 해리상수인 $K_D$는 97 nM이었고, 이 수치는 Class I에 속함을 알 수 있었다.

• Molecules and Cells
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• 제39권6호
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• pp.460-467
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• 2016

Bacteriophytochromes are phytochrome-like light-sensing photoreceptors that use biliverdin as a chromophore. To study the biochemical properties of the Deinococcus radiodurans bacteriophytochrome (DrBphP) protein, two anti-DrBphP mouse monoclonal antibodies (2B8 and 3H7) were generated. Their specific epitopes were identified in our previous report. We present here fine epitope mapping of these two antibodies by using truncation and substitution of original epitope sequences in order to identify minimized epitope peptides. The previously reported original epitope sequences for 2B8 and 3H7 were truncated from both sides. Our analysis showed that the minimal peptide sequence lengths for 2B8 and 3H7 antibodies were nine amino acids (RDPLPFFPP) and six amino acids (PGEIEE), respectively. We further characterized these peptides in order to investigate their reactivity after single deletion and single substitution of the original peptides. We found that single-substituted 2B8 epitope (RDPLPAFPP) and dual-substituted 3H7 epitope (PGEIAD) showed significantly increased reactivity. These two antibodies with high reactivity for the short modified peptide sequences are valueble for developing new peptide tags for protein research.

• Journal of Periodontal and Implant Science
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• 제42권5호
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• pp.166-172
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• 2012

Purpose: The aim of this study was to evaluate the improvement of osteogenic potential of biphasic calcium phosphate (BCP) bone substitute coated with synthetic cell-binding peptide sequences in a standardized rabbit sinus model. Methods: Standardized 6-mm diameter defects were created bilaterally on the maxillary sinus of ten male New Zealand white rabbits, receiving BCP bone substitute coated with synthetic cell binding peptide sequences on one side (experimental group) and BCP bone substitute without coating (control group) on the other side. Histologic and histomorphometric analysis of bone formation was carried out after a healing period of 4 or 8 weeks. Results: Histological analysis revealed signs of new bone formation in both experimental groups (4- and 8-week healing groups) with a statistically significant increase in bone formation in the 4-week healing group compared to the control group. However, no statistically significant difference in bone formation was found between the 8-week healing group and the control group. Conclusions: This study found that BCP bone substitute coated with synthetic cell-binding peptide sequences enhanced osteoinductive potential in a standardized rabbit sinus model and its effectiveness was greater in the 4-week healing group than in the 8-week healing group.

• Clinical and Experimental Reproductive Medicine
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• 제27권2호
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• pp.201-209
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• 2000

Objective: This study has been carried out to evaluation the effect of fertilization promoting peptide (FPP) on the kinematic parameters, capacitation and acrosome reaction of the frozen-thawed human spermatozoa. Methods: After FPP treatment, we examined kinematic parameters, capacitation and acrosome reaction, using the methods of computer-aided sperm analysis (CASA) and chlortetracycline (CTC) fluorescence analysis. Results: We have obtained the evidence that FPP can promote the capacitation and inhibit the spontaneous acrosome reaction of frozen-thawed human spermatozoa in vitro. FPP ($25{\sim}100$ nM) induced a significant increase in the proportion of B-pattem capacitated spermatozoa, and a significant decrease in the proportion of F-pattem uncapacitated ones without significant stimulation of acrosomal exocytosis. In the kinematic parameters treatment, FPP treated groups maint3ined higher LIN, BCF and STR than those of control. The VAP, VSL, VCL and ALH were not different. Therefore it is suggested that FPP in human seminal plasma may play a positive role in promoting human sperm function.

• Bulletin of the Korean Chemical Society
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• 제17권11호
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• pp.1036-1039
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• 1996

Synthetic lipoidal peptides based on viral protein sequences have been prepared. These peptides contain an N-palmitoyl group at the N-terminal residue, which is a modified cysteine, containing a S-[2,3-bis(acyloxy)-(2-R,S)-propyl] moiety. When this residue (Pam3Cys) is at the N-terminus of a synthetic peptide, it acts as potent immunoadjuvant to enhance both IgM and IgG antibody responses to the attached peptide. Conventional analytical procedures (e.g., Edman degradation and amino acid analysis) are either not applicable due to the N-terminal modification, or do not provide confirmation of the intact structure. Chromatographic analysis is also hindered by the tendency of these lipoidal Pam3Cys peptides to form large aggregates, and in some cases to be permanently adsorbed on reversed phase columns. We have applied several mass spectrometric techniques, including fast atom bombardment (FAB), electrospray ionization (ESI) and matrix assisted laser desorption ionization (MALDI) to characterize the intact structures of a number of different Pam3Cys synthetic peptides. The MALDI-MS has been found to be the most sensitive for the analysis of the structure of Pam3Cys peptides.

• Journal of Microbiology
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• 제35권4호
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• pp.347-353
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• 1997

We have characterized a phage library displaying random 22mer peptides which were produced as N-terminal fusions to the pIII coat protein of M13 filamentous phages. Among the sixty phages randomly picked from the library, 25 phages had the 22mer peptide inserts. The DNA sequence analysis of the 25 inserts showed the following results: first, each nucleotide was represented almost equally at each codon position except that there were some biases toward G bases at the first position of the codons. Secondly, the expected 47 sense codons were represented. The deduced amino acid sequences of the 25 inserts were analyzed to examine its diversity. Glycine and glutamate were the two most overrepresented residues above the expected value, whereas cysteine and threonine residues were underrepresented. The range of dicersity in dipeptide sequences showed that the amino acid residues were randomly distributed along the peptide insert. Acidic, basic, polar, and nonpolar amino acid residues were represented to the extent expected at most positions of the peptide inserts. The predicted isoelectric points and hydropathy indices of the 25 peptides showed that a variety of the peptide were represented in the library. These results indicate that this phage display library could be useful in fiuding ligands for a broad spectrum of receptors by affinity screening.

• Asian-Australasian Journal of Animal Sciences
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• 제29권3호
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• pp.315-320
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• 2016

Porcine beta-defensin-1 (PBD-1) gene plays an important role in the innate immunity of pigs. The peptide encoded by this gene is an antimicrobial peptide that has direct activity against a wide range of microbes. This peptide is involved in the co-creation of an antimicrobial barrier in the oral cavity of pigs. The objective of the present study was to detect polymorphisms, if any, in exon-1 and exon-2 regions of PBD-1 gene in Large White Yorkshire (LWY) and native Ankamali pigs of Kerala, India. Blood samples were collected from 100 pigs and genomic DNA was isolated using phenol chloroform method. The quantity of DNA was assessed in a spectrophotometer and quality by gel electrophoresis. Exon-1 and exon-2 regions of PBD-1 gene were amplified by polymerase chain reaction (PCR) and the products were subjected to single strand conformation polymorphism (SSCP) analysis. Subsequent silver staining of the polyacrylamide gels revealed three unique SSCP banding patterns in each of the two exons. The presence of single nucleotide polymorphisms (SNPs) was confirmed by nucleotide sequencing of the PCR products. A novel SNP was found in the 5'-UTR region of exon-1 and a SNP was detected in the mature peptide coding region of exon-2. In exon-1, the pooled population frequencies of GG, GT, and TT genotypes were 0.67, 0.30, and 0.03, respectively. GG genotype was predominant in both the breeds whereas TT genotype was not detected in LWY breed. Similarly, in exon-2, the pooled population frequencies of AA, AG, and GG genotypes were 0.50, 0.27, and 0.23, respectively. AA genotype was predominant in LWY pigs whereas GG genotype was predominant in native pigs. These results suggest that there exists a considerable genetic variation at PBD-1 locus and further association studies may help in development of a PCR based genotyping test to select pigs with better immunity.