• Bulletin of the Korean Chemical Society
• /
• 제32권2호
• /
• pp.620-624
• /
• 2011

In recent years, the study of self-assembly peptide used in drug delivery system has been attracted great interest from scientists. In the category are self-assembly peptides in the structure either with one hydrophobic surface and another hydrophilic or a hydrophobic head and a hydrophilic tail. Here, we focus on a novel designed peptide EYK with double amphiphilic surfaces, investigating on the capability of peptide as a carrier for hydrophobic compound model pyrene. The fluorescence data presented the dynamic process of the transfer, showing that the pyrene was in the crystalline form in peptide solution, and molecularly migrated from its peptide encapsulations into the membrane bilayers when the peptide-pyrene suspension was mixed with liposome vesicles. The results indicated that the peptide EYK could stabilize hydrophobic pyrene in aqueous solution and delivered it into EPC liposome as a potential carrier.

• 한국수산과학회지
• /
• 제54권6호
• /
• pp.927-937
• /
• 2021

This study was performed to screen the antimicrobial activities of the extract from the Pacific oyster Crassostrea gigas against skin pathogens and to purify the relevant antibacterial peptide. The acidified extract showed potent antibacterial activities against gram-positive and gram-negative bacteria but showed no activity against Candida albicans and no significant cell toxicity. Among acne-causing pathogens, the acidified extract showed potent antibacterial activity only against Staphylococcus aureus, and its antibacterial activity was completely abolished by treatment with trypsin or chymotrypsin, and was inhibited by salt treatment. The acidified extract showed strong DNA-binding ability but did not show bacterial membrane permeabilizing ability. Based on antimicrobial activity screening and cytotoxic effects, a novel antibacterial peptide was purified from the acidified gill extract using solid-phase extraction, cation-exchange, and reversed-phase HPLC. The resulting peptide had a molecular weight of 4800.8 Da and showed partial sequence homology with the carbonic anhydrase 4 (CA4) protein in the hard-shelled mussel. Overall, we purified a novel antibacterial peptide, named cgCAFLP, which is related to carbonic anhydrase 4 (CA4) protein, against skin pathogens. Our results suggest that the Pacific oyster extract could be used as an additive to control some acne-related skin pathogens (S. aureus).

• 한국축산식품학회지
• /
• 제37권3호
• /
• pp.402-409
• /
• 2017

A novel peptide having free radical scavenging activity was separated, using an on-line high-performance liquid chromatography (HPLC) - ABTS screening method, from bovine skim milk fermented by Lactococcus lactis SL6 (KCTC 11865BP). It was further purified using reverse phase-HPLC (RP-HPLC) and sequenced by RP-HPLC-tandem mass spectrometry. The amino acid sequence of the identified peptide was determined to be Phe-Ser-Asp-Ile-Pro-Asn-Pro-Ile-Gly-Ser-Glu-Asn-Ser-Glu-Lys-Thr-Thr-Met-Pro-Leu-Trp (2,362 Da), which is corresponding to the C-terminal fragment of bovine ${\alpha}_{s1}$-casein (f179-199). The hydroxyl radicals scavenging activity ($IC_{50}$ $28.25{\pm}0.96{\mu}M$) of the peptide chemically synthesized based on the MS/MS data showed a slightly lower than that of the natural antioxidant Trolox ($IC_{50}$ $15.37{\pm}0.52{\mu}M$). Furthermore, derivatives of the antioxidant peptide were synthesized. The antioxidative activity of the derivatives whose all three proline residues replaced by alanine significantly decreased, whereas replacement of two proline residues in N-terminal region did not affect its antioxidative activity, indicating that $3^{rd}$ proline in C-terminal region is critical for the antioxidative activity of the peptide identified in this study. In addition, N-terminal region of the antioxidant peptide did not show its activity, whereas C-terminal region maintained antioxidative activity, suggesting that C-terminal region of the peptide is important for antioxidative activity.

• Fisheries and Aquatic Sciences
• /
• 제19권9호
• /
• pp.37.1-37.5
• /
• 2016

Human immunodeficiency virus (HIV) is the causative agent of acquired immune deficiency syndrome (AIDS). Anti-HIV agents targeting various steps in HIV life cycle have been developed; however, so far, no effective drugs have been found. We show here that a peptide isolated from Spirulina maxima (SM-peptide) inhibits HIV-1 infection in a human T cell line MT4. SM-peptide inhibited $HIV-1_{IIIB}$-induced cell lysis with a half-maximal inhibitory concentration ($IC_{50}$) of 0.691 mM, while its 50 % cytotoxic concentration ($CC_{50}$) was greater than 1.457 mM. Furthermore, the SM-peptide inhibited the HIV-1 reverse transcriptase activity and p24 antigen production. This suggests that SM-peptide is a novel candidate peptide, which may be developed as a therapeutic agent for acquired immunodeficiency syndrome patients.

• Molecules and Cells
• /
• 제28권5호
• /
• pp.473-477
• /
• 2009

Previously, the 9-mer analog peptides, 9Pbw2 and 9Pbw4, were designed based on a defensin-like peptide, protaetiamycine isolated from Protaetia brevitarsis. In this study, antifungal effects of the analog peptides were investigated. The antifungal susceptibility testing exhibited that 9Pbw4 contained more potent antifungal activities than 9Pbw2. A PI influx assay confirmed the effects of the analog peptides and demonstrated that the peptides exerted their activity by a membrane-active mechanism, in an energy-independent manner. As the noteworthy potency of 9Pbw4, the mechanism(s) of 9Pbw4 were further investigated. The membrane studies, using rhodamine-labeled giant unilamellar vesicle (GUV) and fluorescein isothiocyanate (FITC)-dextran loaded liposome, suggested that the membrane-active mechanism of 9Pbw4 could have originated from the pore-forming action and the radii of pores was presumed to be anywhere from 1.8 nm to 3.3 nm. These results were confirmed by 3D-flow cytometric contour-plot analysis. The present study suggests a potential of 9Pbw4 as a novel antifungal peptide.

• BMB Reports
• /
• 제33권1호
• /
• pp.92-95
• /
• 2000

The HIV-1 p24(202-221) sequence ETINNEEEWDRVHPV HAGP contains a B-cell epitope with the earliest immune response and the highest antibody titer against anti-mouse sera obtained by immunization with p24 antigens. A novel mouse monoclonal antibody (mAb) was generated against the immunodominant B-cell epitope of the HIV-1 p24 capsid protein, p24(202-221). BALB/c mice were immunized with the four branched multiple antigenic peptide (MAP) containing the HIV-1p24(202-221) sequence, and antibody-secreting hybridoma were produced by fusion of mouse splenocytes with P3X63Ag8.653, mouse myeloma cells. One clone which produced the antigen-specific mAb named KI-24 (Isotype IgG1, light chain: ${\kappa}$) was identified. mAb KI-24 was highly specific for both the p24(202-221) and p24 proteins when analyzed by ELISA and Western blotting. Since p24(202-221) also contains a cytotoxic T-lymphocyte epitope, this specfic peptide epitope and the monoclonal antibody with specific reactivity against the p24 protein and p24(202-221) can be used in peptide vaccine development and p24 antigen detection from HIV patients.

• Journal of Microbiology and Biotechnology
• /
• 제11권5호
• /
• pp.798-803
• /
• 2001

Peptide synthetases produced from various microorganisms are multifunctional enzyme complexes and their substrates are recognized and activated by adenylation domains. To identify the substrate specificity of the peptide synthetase isolated from Bacillus subtilis 713, known to produce an antifungal peptide, two adenylation domains containing the minimal functional portion were expressed and purified. ATP-ppi exchange experiments and kinetic studies revealed that the two adenylation enzymes had a substrate specificity to $_{L}-lysine{\;}and{\;}_{L}-tryptophan$, respectively. In addition, based on a signature sequence comparison, the substrate of the third domain was predicted to be L-glutamic acid. These results suggest that this peptide synthetase is novel because there has been no previous report on a peptide synthetase that uses $_{L}-lysine,{\;}_{L}-tryptophan,{\;}and{\;}_{L}-glutamic$ acid as substrates in that order.

• Bulletin of the Korean Chemical Society
• /
• 제33권9호
• /
• pp.3004-3008
• /
• 2012

Small molecule conjugated peptides were prepared by solid-phase synthesis as potential novel whitening agents, and their melanogenesis inhibitory activities were investigated. The conjugated small molecules were well-known materials as tyrosinase inhibitors, and peptides were selected from the sequences that are known to antagonize melanocortin receptor 1 (MC1R). Most of small molecules-peptide conjugates showed superior melanin inhibition activity to kojic acid and arbutin. Among these, almost all compounds have -AR- sequence. From this study, we concluded that the small molecule conjugated peptides containing -AR- sequence have melanogenesis inhibitory activities and have potential to be used as novel whitening agents.

• Journal of Microbiology and Biotechnology
• /
• 제25권6호
• /
• pp.788-794
• /
• 2015

Cationic liposomes have been actively used as gene delivery vehicles despite their unsatisfactory efficiencies because of their relatively low toxicity. In this study, we designed novel heterodimeric peptides as nonviral gene delivery systems from TAT and NLS peptides using cysteine-to-cysteine disulfide bonds between the two. Mixing these heterodimeric peptides with DNA before mixing with lipofectamine resulted in higher transfection efficiencies in MCF-7 breast cancer cells than mixing unmodified TAT, NLS, and a simple mixture of TAT and NLS with DNA, but did not show an adverse effect on cell viability. In gel retardation assays, the DNA binding affinities of heterodimeric peptides were stronger than NLS but weaker than TAT. However, this enhancement was only observed when heterodimeric peptides were premixed with DNA before being mixed with lipofectamine. The described novel transfection-enhancing peptide system produced by the heterodimerization of TAT and NLS peptides followed by simple mixing with DNA, increased the gene transfer efficiency of cationic lipids without enhancing cytotoxicity.

• 공업화학
• /
• 제23권5호
• /
• pp.429-432
• /
• 2012

최근 항생제에 대한 내성이 빠르게 확산됨에 따라 이를 극복하기 위해 새로운 항생제들을 찾기 위한 노력이 많은 연구자들에 의해 이루어지고 있다. 미생물의 외부공격에 대해 모든 생명체들은 방어물질을 분비하거나 내재하고 있는 데 그 중 하나가 항균 펩타이드이며, 전 세계적으로 활발한 연구가 이루어지고 있고 새로운 차세대 항생제로써 인식 되어진다. 이에 본 총설에서는 항균 펩타이드의 미생물에 대한 항생활성, 작용기작과 개발현황에 대해 고찰하고자 한다.