• Biotechnology and Bioprocess Engineering:BBE
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• 제6권4호
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• pp.244-251
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• 2001

Over half of all biologically active peptide and peptide hormones are $\alpha$-amidated at their C-terminus, which is essential for their full biological activities. Amidation is accomplished through the sequential reaction of the two enzymes encoded by the single bifunctional, peptidyl-glycine $\alpha$-amidating monooxygenase (PAM or an $\alpha$-amidating enzyme). PAM catalyze the forma - tion of a peptide amide from peptide precursors that include a C-terminal glycine, and requires copper molecular oxygen and ascorbate. PAM is the only enzyme that produces peptide amides in vivo. However various strategies utilizing PAM, carboxypeptidase-Y enzymes, and chemical syn-thesis have been developed for producing peptide amides in vitro. The growing need and impor-tance of peptide amide drugs has highlighted the necessity for a efficient in vitro amidating sys-tem for industrial application for the production of peptide hormones, like calcitonin and oxytocin. This review presents the current situation regarding amidation with a special emphasis on the in-dustrial production or peptide hormones.

• Journal of Applied Biological Chemistry
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• 제59권3호
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• pp.239-242
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• 2016

A novel Nicotinoyl fused peptide, Nicotinoyl-LVH, was synthesized by solid phase peptide synthesis method, purified, and tested in cultured skin cells. Nicotinoyl-LVH enhanced the expression level of collagen mRNA and its fragments in fibroblasts. These data show that this novel Nicotinoyl peptide is a promising biomaterial in the anti-aging functional cosmetic market.

• Fisheries and Aquatic Sciences
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• 제24권4호
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• pp.163-170
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• 2021

Peptides are naturally occurring biological molecules that are found in all living organisms. These biologically active peptides play a key role in various biological processes. The aim of this study is the extraction and the purification of bioactive materials that induce relaxation of an apical muscle from the pyloric caeca of Patiria pectinifera. The acidified pyloric caeca extract was partially separated by the solid phase extraction using a stepwise gradient on Sep-Pak C18 cartridge. Among the fractions, materials eluted with 60% methanol/0.1% trifluoroacetic acid was put a thorough of a series of high performance liquid chromatography (HPLC) steps to isolate a neuropeptide with relaxation activity. The purified compound was eluted at 28% acetonitrile in 0.1% trifluoroacetic acid with retention time of 25.8 min on the CAPCELL-PAK C18 reversed-phase column. To determine the molecular weight and the amino acid sequence of the purified peptide, LC-MS and Edman degradation method were used, respectively. The primary structure of the peptide was determined to be FGMGGAYDPLSAGFTD which corresponded to the amino acid sequence of a starfish myorelaxant peptide (SMP) isotype (SMPb) found in the cDNA sequence encoding SMPa and its isotypes. In this study, a muscle relaxant neuropeptide (SMPb) has been isolated from pyloric caeca of starfish P. pectinifera. This is the first report of SMPb isolation on the protein level from P. pectinifera.

• 약학회지
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• 제57권2호
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• pp.125-131
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• 2013

Biologically active peptides, including growth factors and cytokines, participate in various biological processes in human skin. They could provide a great advantage of maintaining healthy skin. Many peptide growth factors like epidermal growth factor (EGF) and human growth hormone (hGH) have been used in cosmetic formulations. The delivery of peptide growth factors across the Stratum corneum, however, seems not sufficient because of their physical properties such as high molecular weight and hydrophilicity. So increasing the penetration of growth factors of interest into skin would be a major concern for ensuring their maximum biological efficacy. In this study, we have identified several skin penetration-enhancing peptides which facilitate delivery of growth factors, when fused at N-terminus of the target protein, into skin. For efficient and rapid screening, we constructed a skin-penetrating assay system using Franz cell and porcine skin. Next, we carried out phage display screening using M-13 bacteriophage with random 12 -amino acid library on its coat protein P3 on that system. After several selection rounds, peptide sequences facilitate the penetration of phages through the porcine skin were identified from a large population of phages. We found that phages with the most potent peptide (S3-2, NGSLNTHLAPIL) could penetrate the porcine skin eight times more than those with control peptide (12 mino acids scrambled peptide). Furthermore, growth factors conjugated with S3-2 peptide penetrate porcine skin three to five times efficiently than non-conjugated growth factors. In conclusion, our data shows that the skin penetration-enhancing peptide we have characterized could increase the delivery of growth factors and is useful for cosmeceutical application.

• 한국고분자학회:학술대회논문집
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• 한국고분자학회 2006년도 IUPAC International Symposium on Advanced Polymers for Emerging Technologies
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• pp.261-261
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• 2006

Membranes are a central feature of all biological systems and their ability to control many cellular processes is critically important. As a result, a better understanding of how molecules bind to biological membranes is an active area of research. In this report, the interaction between our biomimetic structures and different biological membranes is reported using both model vesicle and in vitro bacterial cell experiments. These results show that lipid composition is more important for selectivity than overall net charge. An effort is made to connect model vesicle studies with in vitro data and naturally occurring lipid compositions.

• Journal of Microbiology and Biotechnology
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• 제8권1호
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• pp.34-41
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• 1998

A method was developed for the controlled expression of an antimicrobial peptide magainin in Escherichia coli. A series of concatemeric magainin genes was constructed with a gene amplification vector, and fused to the 3'end of malE gene encoding the affinity ligand, E. coli maltose-binding protein (MBP). The construct directed the synthesis of the fusion protein with the magainin polypeptide fused to the C-terminus of MBP. The fusion protein was expressed in a tightly regulatable expression system which was under the control of an invertible promoter. The MBP-fused magainin monomer was expressed efficiently. However, the expression level of the MBP-fused magainin in E. coli decreased with the increasing size of multimers possibly because of the transcription and translation inhibition by the multimeric peptides. After purification using an amylose affinity column, the fusion protein was digested by factor Xa at a specific cleavage site between the monomers. The recombinant magainin had an antimicrobial activity identical to that of synthetic magainin. This experiment shows that a biologically active, antimicrobial peptide magainin can be produced by fusing to MBP, along with a promoter inversion vector system.

• BMB Reports
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• 제56권11호
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• pp.606-611
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• 2023

The main protease (Mpro) of SARS-CoV-2 cleaves 11 sites of viral polypeptide chains and generates essential non-structural proteins for viral replication. Mpro is an important drug target against COVID-19. In this study, we developed a real-time fluorometric turn-on assay system to evaluate Mpro proteolytic activity for a substrate peptide between NSP4 and NSP5. It produced reproducible and reliable results suitable for HTS inhibitor assays. Thus far, most inhibitors against Mpro target the active site for substrate binding. Mpro exists as a dimer, which is essential for its activity. We investigated the potential of the Mpro dimer interface to act as a drug target. The dimer interface is formed of domain II and domain III of each protomer, in which N-terminal ten amino acids of the domain I are bound in the middle as a sandwich. The N-terminal part provides approximately 39% of the dimer interface between two protomers. In the real-time fluorometric turn-on assay system, peptides of the N-terminal ten amino acids, N10, can inhibit the Mpro activity. The dimer interface could be a prospective drug target against Mpro. The N-terminal sequence can help develop a potential inhibitor.

• The Korean Journal of Physiology and Pharmacology
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• 제2권5호
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• pp.637-644
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• 1998

Previously, we have isolated authentic bombesin and another bombesin like peptide named bombesin like immunoreactivity (BLI)-K2 from the skin of Korean fire-bellied toad, Bombina orientalis. In the present study, we have newly purified three heterogeneous forms of BLI named BLI-K3, BLI-K4, and BLI-K5 from side fractions obtained in previous isolation of bombesin like peptide. The BLIs were separated into five peaks on a column of $C_{18}$ preparative HPLC. Among them, three minor peaks containing BLI-K3, K4, and K5 were purified by means of sequential chromatography on the columns of SP cation exchange HPLC and $C_{18}$ reverse phase HPLC. The purified BLI-K3 and K4 showed high binding affinity to an anti-bombesin serum (LBE 2G-2) with binding potency of 72 and 95%, respectively, relative to that of bombesin. However, they did not possess any distinctive biological activity of bombesin like peptide. On the contrary, the biological activity of BLI-K5 was similar to that of bombesin but its binding affinity to an anti-bombesin serum was low. The results indicate that three heterogeneous forms of BLI were coexpressed with bombesin and BLI-K2 in the skin of B. orientalis. All forms of the purified BLI in the present study were immunologically active but only BLI-K5 possessed the distinctive biological activity of bombesin like peptide.

• 생명과학회지
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• 제12권4호
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• pp.477-482
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• 2002

효모 glucoamylase의 promoter와 분비신호서열 그리고 MF$\alpha$1의 prosequence를 이용하여 곤충 defensin을 S. cerevisiae 2805에서 항균활성을 보유한 형태로 발현 및 분비하는데 성공하였다. 발현된 defensin의 대부분이 세포 외로 분비되어 거의 모든 항균활성이 배양 상등액에 존재하였다. 이것은 S. cerevisiae에서 발현된 defensin이 glucoamylase의 분비신호서열과 MF$\alpha$1의 prosequenre에 의해 효율적으로 processing되어 분비됨을 시사한다. Defensin의 다른 미생물에 대한 항균활성을 조사한 결과 병원균인 St. aureus와 L. monocytogenes에 대해서도 항균활성이 존재하였다.

• The Korean Journal of Physiology and Pharmacology
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• 제21권6호
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• pp.667-674
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• 2017

Angiotensin II (Ang II) is metabolized from N-terminal by aminopeptidases and from C-terminal by Ang converting enzyme (ACE) to generate several truncated angiotensin peptides (Angs). The truncated Angs have different biological effects but it remains unknown whether Ang-(4-8) is an active peptide. The present study was to investigate the effects of Ang-(4-8) on hemodynamics and atrial natriuretic peptide (ANP) secretion using isolated beating rat atria. Atrial stretch caused increases in atrial contractility by 60% and in ANP secretion by 70%. Ang-(4-8) (0.01, 0.1, and $1{\mu}M$) suppressed high stretch-induced ANP secretion in a dose-dependent manner. Ang-(4-8) ($0.1{\mu}M$)-induced suppression of ANP secretion was attenuated by the pretreatment with an antagonist of Ang type 1 receptor ($AT_1R$) but not by an antagonist of $AT_2R$ or $AT_4R$. Ang-(4-8)-induced suppression of ANP secretion was attenuated by the pretreatment with inhibitor of phospholipase (PLC), inositol triphosphate ($IP_3$) receptor, or nonspecific protein kinase C (PKC). The potency of Ang-(4-8) to inhibit ANP secretion was similar to Ang II. However, Ang-(4-8) $10{\mu}M$ caused an increased mean arterial pressure which was similar to that by 1 nM Ang II. Therefore, we suggest that Ang-(4-8) suppresses high stretch-induced ANP secretion through the $AT_1R$ and $PLC/IP_3/PKC$ pathway. Ang-(4-8) is a biologically active peptide which functions as an inhibition mechanism of ANP secretion and an increment of blood pressure.