Department of Biochemistry, Faculty of Science, Khon Kaen University, Khon Kaen, Thailand.
Department of Bioscience, School of Agriculture, Tokai University, Kumamoto, Japan.
J Antibiot (Tokyo). 2014 Mar;67(3):205-12. doi: 10.1038/ja.2013.114. Epub 2013 Nov 6.
Leucrocin I is an antibacterial peptide isolated from crocodile (Crocodylus siamensis) white blood cell extracts. Based on Leucrocin I sequence, cationic peptide, NY15, was designed, synthesized and evaluated for antibacterial activity against Bacillus sphaericus TISTR 678, Bacillus megaterium (clinical isolate), Vibrio cholerae (clinical isolate), Salmonella typhi (clinical isolate), Salmonella typhi ATCC 5784 and Escherichia coli 0157:H7. The efficacy of the peptide made from all L-amino acids was also compared with all D-amino acids. The peptide made from all D-amino acids was more active than the corresponding L-enantiomer. In our detailed study, the interaction between peptides and the cell membrane of Vibrio cholerae as part of their killing mechanism was studied by fluorescence and electron microscopy. The results show that the membrane was the target of action of the peptides. Finally, the cytotoxicity assays revealed that both L-NY15 and D-NY15 peptides are non-toxic to mammalian cells at bacteriolytic concentrations.
亮氨酸脑啡肽 I 是从鳄鱼（暹罗鳄）白细胞提取物中分离得到的一种抗菌肽。基于亮氨酸脑啡肽 I 的序列，设计、合成并评估了阳离子肽 NY15 对球形芽孢杆菌 TISTR 678、巨大芽孢杆菌（临床分离株）、霍乱弧菌（临床分离株）、伤寒沙门氏菌（临床分离株）、伤寒沙门氏菌 ATCC 5784 和大肠杆菌 0157:H7 的抗菌活性。还比较了由全 L-氨基酸和全 D-氨基酸制成的肽的功效。由全 D-氨基酸制成的肽比相应的 L-对映体更具活性。在我们的详细研究中，通过荧光和电子显微镜研究了肽与霍乱弧菌细胞膜之间的相互作用，作为其杀伤机制的一部分。结果表明，细胞膜是这些肽的作用靶标。最后，细胞毒性测定表明，在溶菌浓度下，L-NY15 和 D-NY15 肽对哺乳动物细胞均无毒性。
