• Journal of Microbiology
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• 제34권3호
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• pp.274-278
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• 1996

Two peptides, MA-inv AND MA-ME, with the sequence 10-17 of maganin 2 at their-N-termini were designed and synthesized. The peptides had higher antifungal activities against Aspergilus fumigatus without hemolytic activities. The minimal inhibition concentratory (MIC) values of both peptides against A. fumigatus were 5 .mu.g/ml, whereas those of the native peptides, magainin 2 and melittin, were 10.mu.g/ml. At 3 .mu.g/ml, MA-inv and MA-ME inhibited the mycelium growth of A. fumigatus by 94.6% and 97.3% respectively, whereas magainin 2 and melittin inhibited by 62.2% and 32.4, respectively. MA-inv showed up to 80% inhibition of (1, 3)-.betha.-D-glucan synthase activity of A. fumigatus. The peptides also showed up to 80% inhibition of (1, 3)-.betha.-D glucan synthase activity of A. fumigatus. The peptides also showed antifungal activities for other fungi of Aspergillus sp. However, the antibiotic activities of MA-ME against Escherichia coli, Bacillus subtilis and Fusarium oxysporum were more effective than those of MA-inv, suggesting that the C-terminal sequences of MA-inv and MA-ME may also influence their antibiotic activities. These results suggest that the N-terminal sequence of the designed peptides, KKFGKAFV, is important for their antifungal activities against A. fumigatus and their C- terminal sequences are related to the organism selectivity.

• 미생물학회지
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• 제40권3호
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• pp.211-216
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• 2004

세포외 phospholipase D (PLD)를 과량 생산하는 균주 JE-11을 토양으로부터 분리하였다. 16S rDNA에 의한 분석과 형태적, 생리적 특성을 조사한 결과 이 균은 Streptomyces somaliensis로 동정되었다. 선발한 S. somaliensis로 부터 PLD를 암호화하는 유전자(sspld) 분리하고 염기서열을 조사하였다. Open reading frame을 분석한 결과 33개의 아미노산으로 이루어진 분비 signal peptide와 505개의 아미노산으로 구성된 PLD단백질을 암호화하는 것으로 예상되었다. 또한, sspld의 염기 서열로부터 유추된 단백질 서열은 기존에 보고된 다른 Streptomyces PLD들과 70-88％의 서열 유사성을 보였다. 이 PLD는 96-98％(㏖/㏖)의 수율로서, Phosphatidylcholine을 glycerol과 serine을 기질로 하여 각각 phosphatidylglycerol 과phosphatidylserine으로 전환을 하였으나, 알코올 공여체인 inositol과 ethanolamine과는 반응하지 않았다.

• BMB Reports
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• 제38권3호
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• pp.290-293
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• 2005

In order to investigate the epitope of basic fibroblast growth factor (bFGF) and its immunogenicity, the epitopes of bFGF were screened from the phage display library with monoclonal antibody GF22, which can neutralize the bio-activity of bFGF. By three rounds of screening, the positive phage clones with bFGF epitopes were selected, which can effectively block the bFGF to bind with GF22. Sequence analysis showed that the epitopes shared a highly conservative sequence (Leu-Pro-Pro/Leu-Gly-His-Phe/Ile-Lys). The sequence of PPGHFK was located at 22-27 of the bFGF. The specific immuno-response of mouse could be highly induced by phage clones with the epitopes. And the anti-bFGF activity induced by LPGHFK was 3 times higher than the original sequence, which showed that the mimetic peptide LPLGHIK might be used as a tumor vaccine in the prevention and treatment of tumor.

• Molecules and Cells
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• 제26권1호
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• pp.34-40
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• 2008

To express an increased level of recombinant Mefp1 (marine mussel adhesive protein) in soluble form, we constructed expression vectors encoding truncated OmpA signal peptide-Mefp1 fusion proteins. OmpA signal peptide (OmpASP) is the 21 residue peptide fragment of the 23 residue OmpA signal sequence cleavable by signal peptidase I. We successfully produced increased levels of soluble recombinant Mefp1 (rMefp1) with various deletions of OmpASP, and found that the increased expression was caused by the increased pI of the N-terminus of the fusion proteins (${\geq}10.55$). All the OmpA signal peptide segments of 3-21 amino acids in length had the same pI value (10.55). Our results suggest that the pI value of the truncated OmpASP ($OmpASP_{tr}$) play an important role in directional signaling for the fusion protein, but we found no evidence for the presence of a secretion enhancer in OmpASP. For practical applications, we increased the expression of soluble rMefp1 with $OmpASP_{tr}$ peptides as directional signals, and obtained rMefp1 with the native amino terminus (nN-rMefp1) using an $OmpASP_{tr}$ Xa leader sequence that contains the recognition site for Xa protease.

• 대한미생물학회지
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• 제22권2호
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• pp.167-174
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• 1987

N-myc, a DNA sequence related to the oncogene c-myc, was found to be amplified in untreated primary neuroblastomas and the amplification appeared to be associated with advanced disease at diagnosis and rapid tumor progression. Synthetic peptides have been useful immunogens for generating antisera and monoclonal antibodies to a number of native proteins. In order to identify myc-related protein in the tumor cells, an antiserum against a synthetic hexapeptide (-Glu-Asp-Ile-Trp-Lys-Lys-), whose sequence corresponds to a part of the exon 2 of oncogene N-myc, was prepared by immunizing a rabbit with BSA-conjugated peptide. After ammonium sulfate precipitation and affinity column chromatography, it appeared to be specific to the peptide. Strong nuclear staining in immunoperoxidase method using this serum was observed in both human promyeloid leukemic cell line, HL-60(containing high c-myc copy number), and human neuroblastoma cell line, LA-N-5 (containing high N-myc copy number), whereas LA351 (human lymphoid cell line) cells did not react with the serum. This reaction was completely abrogated by incubating the antiserum with soluble excess peptide. These data suggest that the protein encoded by N-myc could be localized in the nucleus as c-myc protein and this antiserum can be used to detect myc-related tumor cells in clinical samples and to determine if the N-myc expression correlates with genomic amplification in cell lines, untreated primary tumors, and untreated metastases.

• Molecules and Cells
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• 제46권11호
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• pp.700-709
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• 2023

Mucus hyperproduction and hypersecretion are observed often in respiratory diseases. MUC8 is a glycoprotein synthesized by epithelial cells and generally expressed in the respiratory track. However, the physiological mechanism by which extracellular nucleotides induce MUC8 gene expression in human airway epithelial cells is unclear. Here, we show that UTP could induce MUC8 gene expression through P2Y2-PLCβ3-Ca²⁺ activation. Because the full-length cDNA sequence of MUC8 has not been identified, a specific siRNA-MUC8 was designed based on the partial cDNA sequence of MUC8. siRNA-MUC8 significantly increased TNF-α production and decreased IL-1Ra production, suggesting that MUC8 may downregulate UTP/P2Y2-induced airway inflammation. Interestingly, the PDZ peptide of ZO-1 protein strongly abolished UTP-induced TNF-α production and increased IL-1Ra production and MUC8 gene expression. In addition, the PDZ peptide dramatically increased the levels of UTP-induced ZO proteins and TEER (trans-epithelial electrical resistance). These results show that the anti-inflammatory mucin MUC8 may contribute to homeostasis, and the PDZ peptide can be a novel therapeutic candidate for UTP-induced airway inflammation.

• Mycobiology
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• 제39권1호
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• pp.67-69
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• 2011

A cell-free extract of Saccharomyces cerevisiae containing the angiotensin I-converting enzyme (ACE) inhibitory peptide was treated in a successive simulated gastric-intestinal bioreactor (step 1: amylase digestion, step 2: gastric fluid digestion, step 3: intestinal fluid digestion) to illustrate the absorption pattern of antihypertensive ACE inhibitory peptide, and the ACE inhibitory activities of each step were determined. Total ACE inhibitory activities of step 1, step 2, and step 3 were 55.96%, 80.09%, and 76.77%, respectively. The peptide sequence of each steps was analyzed by MS/MS spectrophotometry. Eleven kinds of representative peptide sequences were conserved in each step, and representative new peptides including RLPTESVPEPK were identified in step 3.

• Fisheries and Aquatic Sciences
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• 제15권3호
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• pp.183-190
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• 2012

The purpose of this study was the purification and characterization of an angiotensin I converting enzyme (ACE) inhibitory peptide purified from enzymatic hydrolysates of rainbow trout Oncorhynchus mykiss muscle. After removal of lipid, the approximate composition analysis of the rainbow trout revealed 24.4%, 1.7%, and 68.3% for protein, lipid, and moisture, respectively. Among six hydrolysates, the peptic hydrolysate exhibited the highest ACE inhibitory activity. We attempted to purify ACE inhibitory peptides from peptic hydrolysate using high performance liquid chromatography on an ODS column. The $IC_{50}$ value of purified ACE inhibitory peptide was $63.9{\mu}M$. The amino acid sequence of the peptide was identified as Lys-Val-Asn-Gly-Pro-Ala-Met-Ser-Pro-Asn-Ala-Asn, with a molecular weight of 1,220 Da, and the Lineweaver-Burk plots suggested that they act as a competitive inhibitor against ACE. Our study suggested that novel ACE inhibitory peptides purified from rainbow trout muscle protein may be beneficial as anti-hypertension compounds in functional foods.

• Mass Spectrometry Letters
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• 제12권4호
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• pp.137-145
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• 2021

Herein we report multiple ion mobility (IM) peaks in electrospray ionization IM mass spectrometry (ESI-IM-MS) produced by glutamine residue in peptide. The mobility features of 147 peptides were investigated using ESI-IM-MS combined with liquid chromatography. Of these peptides, 66 presented multiple IM peaks, and analysis of their sequence using collision induced dissociation (CID) revealed that glutamine (Gln), as well as proline (Pro), plays a critical role in generating multiple IM peaks. Mutant-based investigations using Gln-containing peptides indicate that the side chain of Gln promotes intermolecular interactions, inducing multiple structures of the peptide ions in the gas phase. Consequently, the present study demonstrates that the distinct ion mobility signatures identified herein can potentially be used to characterize glutamine-containing peptide ions.

• Journal of Microbiology and Biotechnology
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• 제15권3호
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• pp.656-659
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• 2005

Small peptides synthesized by nonribosomal peptide synthetases (NRPSs) genes are found in bacteria and fungi. While some microbial taxa have few, others make a large number and variety. However, biochemical characterization of the products synthesized by NPRS demands a great deal of efforts. Since the completion of genome projects of numerous microorganisms, the numbers of available NRPSs genes are being expanded. Prediction of the peptides encoded by NRPS could save time and efforts. We chose the NRPS gene from Bradyrhizobium japonicum as a model to predict the peptide structure encoded by NRPS genes. Using computational analyses, the domain structure of this gene was defined, and the structure of a peptide synthesized by this NRPS was deduced. It was found that it encoded a tripeptide consisting of proline-serine-phenylalanine. This method would be helpful to predict the structure of small peptides with various NPRS genes from the genome sequence.