• 한국미생물·생명공학회지
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• 제28권4호
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• pp.195-201
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• 2000

Glucoamylase of Saccharomyces diastaticus is produced as a large precursor composed of signal peptide (21 amino acid residues), Thr and Ser-rich region and functional glucoamylase. To evaluate the utility of the glucoamylase signal peptide (GSP) for the secretion of foreign proteins, four types of GSP mutants (ml : Pro-18 longrightarrowLeu-18, m2 : Tyr-13 longrightarrowLeu, m3 : Ser-9longrightarrowLeu-9, m4 : Asn-5 longrightarrowPro-5) were constructed and secretion efficiency of each mutant was compared with that of native GSP by the expression and secretion of Bacillus subtilis CMCase under the control of GAP in N-terminal domain and hydrophobic domain. n mutant 4, a polar amino acid was replaced by a helix - breaking Pro residue. CMCase activity assay and Western blot analysis revealed that CMCase secretion by GSP mutants replaced by Leu were increased compared with native GSP. In the case of m2 and m3, the substitution of Leu for Tyr-13 and Ser-9 in the hydrophobic region resulted in a twofold increase in the extracellular CMCase activity.

• Journal of Microbiology and Biotechnology
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• 제30권9호
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• pp.1387-1394
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• 2020

Clam worms (Marphysa sanguinea) are a rich source of bioactive components such as the antibacterial peptide, perinerin. In the present study, we explored the physiological activities of a novel NCWPFQGVPLGFQAPP peptide (NCW peptide), which was purified from clam worm extract through high-performance liquid chromatography. Tandem mass spectrometry (MS/MS) revealed that NCW was a new peptide with a molecular weight of 1757.86 kDa. Moreover, NCW peptide exhibited significant antioxidant effects, causing a 50% inhibition of DPPH radical at a concentration of 20 μM without showing any cytotoxicity. These were associated with a reduction in the activity of catalase (CAT), superoxide dismutase (SOD), glutathione peroxidase (GSH-Px), and malondialdehyde (MDA) in LPS-stimulated RAW264. 7 cells. Furthermore, NCW peptide exhibited anti-inflammatory effects in LPS-stimulated RAW264.7 macrophages via inhibition of the abnormal production of pro-inflammatory cytokines including nitric oxide (NO), inducible nitric oxide synthase (iNOS), and cyclooxygenase-2 (COX-2). These anti-inflammatory effects of NCW peptide were associated with the inhibition of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). Our results therefore suggest that this novel NCW peptide with antioxidant and anti-inflammatory effects could be a good therapeutic agent against inflammation-related diseases.

• BMB Reports
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• 제44권10호
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• pp.669-673
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• 2011

Human methionine sulfoxide reductase B3A (hMsrB3A) is an endoplasmic reticulum (ER) reductase that catalyzes the stereospecific reduction of methionine-R-sulfoxide to methionine in proteins. In this work, we identified an antimicrobial peptide from hMsrB3A protein. The N-terminal ER-targeting signal peptide (amino acids 1-31) conferred an antimicrobial effect in Escherichia coli cells. Sequence and structural analyses showed that the overall positively charged ER signal peptide had an Argand Pro-rich region and a potential hydrophobic ${\alpha}$-helical segment that contains 4 cysteine residues. The potential ${\alpha}$-helical region was essential for the antimicrobial activity within E. coli cells. A synthetic peptide, comprised of 2-26 amino acids of the signal peptide, was effective at killing Gram-negative E. coli, Klebsiella pneumoniae, and Salmonella paratyphi, but had no bactericidal activity against Gram-positive Staphylococcus aureus.

• Bulletin of the Korean Chemical Society
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• 제31권1호
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• pp.209-212
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• 2010

• 한국미생물·생명공학회지
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• 제40권4호
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• pp.409-413
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• 2012

인돌리시딘(indolicidin)은 소의 호중구(bovine neutrophils)로 부터 분리된 13개의 아미노산 잔기로 이루어 지고, 트립토판(tryptophan)을 많이 함유한 항균 펩타이드(antimicrobial peptide)이다. 인돌리시딘은 강력한 항균활성과 더불어 mammalian cells에 대해 독성을 나타낸다. 본 연구에서는 인돌리시딘 보다 서열이 짧으며, 보다 증가된 원핵세포 선택성(박테리아세포에 대해 독성을 나타내지만 mammalian cells에 대해서는 독성을 나타내지 않음을 의미함)을 지닌 새로운 짧은 항균 펩타아드를 개발하기 위해, 몇 종의 인돌리시딘 유사체 펩타이드를 설계하고 합성하였다. 결과적으로, 인돌리시딘 보다 서열이 짧으며(10개의 아미노산 잔기로 이루어짐), 증가된 원핵세포선택성을 지닌 4종의 새로운 펩타이드(SI, SI-PA, SI-WF 및 SI-WL)를 개발하였다. 본 연구를 통하여 가장 높은 원핵세포선택성을 나타내는 인돌리시딘 유사체 펩타이드 SI의 항균활성에는 중앙부위에 위치하는 소수성 및 방향족 아미노산이 중요하며, 2군데의 프로린(proline) 잔기는 중요하지 않다는 것을 알았다. 인돌리시딘과 유사체 펩타이드에 대한 원핵세포 선택성은 SI>SI-PA>SI-WF>SI-WL>ID>SI-WA의 순서 이였다. 따라서, 본 연구에서 설계되고 합성한 4종의 인돌리시딘 유사체 펩타이드(SI, SI-PA, SI-WF 및 SI-WL)는 박테리아 감염의 치료제로서 개발될 수 있을 것이다.

• Journal of Microbiology and Biotechnology
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• 제28권5호
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• pp.707-717
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• 2018

Leukocytes are reportedly the first line of the innate immune defense and essential for the control of common bacterial infections. Therefore, in this work, the antibacterial activity of crocodile leukocyte extract against Propionibacterium acnes was evaluated, and we also characterized the related activity of skin infection. The leukocyte extract showed the minimum inhibitory concentration to be $100{\mu}g/ml$ to P. acnes. SEM imaging demonstrated that the leukocyte extract adversely affected P. acnes cell permeability in a concentration-dependent manner. Furthermore, the crocodile leukocyte extract could significantly reduce proinflammatory markers and decrease inflammatory signs in infected mouse ears. The crude leukocyte extract was further purified using FPLC and RP-HPLC. The resulting fraction F5 was indicated as the anti-acne peptide-containing fraction. The molecular mass of the peptide contained in F5 was calculated to be 4,790.5 Da. N-Terminal sequencing revealed the amino acid sequence as GPEPVPAIYQ, which displays similarities to immunoglobulin A and leucine-rich repeat neuronal protein. This is the first reported amino acid sequence of a crocodile leukocyte extract that possesses anti-acne activity. To attempt to use it in a prototype cosmetic, an anti-acne gel containing crude crocodile leukocyte extract was formulated, resulting in seven gel formulations (G1, G2, G3, G4, G5, G6, and G7). The formulations G5, G6, and G7 exhibited 2-fold higher anti-acne activity than G1-G4. Investigation of accelerating stability studies of anti-acne gel formulations G5, G6, and G7 demonstrated that a low storage temperature ($4^{\circ}C$) is suitable for maintaining the physical properties and biological activity of the anti-acne gel products.

• 미생물학회지
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• 제45권1호
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• pp.54-57
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• 2009

대두발효식품인 청국장에는 다양한 항산화물질, peptide 등의 생리활성물질이 존재한다. 청국장 ethanol 추출물은 285 nm에서 0.55의 흡광도 값을 보여 주었다. 이 영역에는 phenol을 포함한 아미노산 및 peptide류가 포함되어 있다고 알려져 있다. 1,1-diphenyl-2-picrylhydrazyl (DPPH)방법으로 청국장의 항산화도를 측정했을 때, ethanol 추출물의 농도가 증가할수록 항산화도는 증가하였다. 무염 생청국장 30 g을 복용하고 2시간 마다 혈압을 측정하였다. 수축기혈압은 복용 후 6시간 지난 후, 평균혈압이 14 mmHg 떨어졌고, 이완기혈압은 8 mmHg 떨어지는 등 혈압강하 효과가 뚜렷하였다. 청국장에 존재하는 daidzein, 항산화물질, Lys-Pro과 같은 angiotensin I-converting enzyme (ACE) 억제제 등이 복합적으로 작용하면서 혈압강하에 기여할 수 있을 것이다.