动物营养学报2011，Vol.23Issue(2)：241-249,9.DOI:10.3969/j.issn.1006-267x.2011.02.009
猪乳铁蛋白肽的分子改良及改良肽的生物学活性研究
Molecular Improvement of Porcine Lactoferricin and Biological Activity of the Modified Peptides
摘要
Abstract
In this study , porcine lactoferricin LFP-20 and its analogs were prepared by chemical synthesis with an aim to understand structure-function relationships of these peptides and thereby to obtain improved analogs. The mimmum inhibitory concentration ( MIC) measured by broth microdilution method and hemolytic analysis showed that the 20-residue porcine lactoferricin ( LFP-20) and its analogs LF2A, LF-1, and LF-3 displayed the antimicrobial activity against Escherichia coli, Salmonella choleraesuis, Salmonella typhimurium, Staphylococcus aureus and Staphylococcus epidermidis. The minimum inhibitory concentrations of LFP-20 ranged from 64 to 128 μg/mL, and LF-1 and LF-3 were 2 to 4 times more effective than LFP-20. The studies demonstrated that the analog LF2A, replacing the 2- and 17- Cys of LFP-20 with Ala , did not show increased activities against bacteria, but exhibited decreased hemolytic activity. The analog LF-1 , replacing the 9-and 18- Ile of LFP-20 with Trp ,showed improved antimicrobial activity. But the hemolytic activity of LF-1 was also increased at 4, 32, 64,128, and 256 μg/mL (P ＜0. 05) . The cytotoxic potential of LFP-20 analogs was quantified by colorimetric WST-1 and LDH assays in peripheral blood mononuclear cell ( PBMC) . LF2A, LF-1 and LF-3 increased cell proliferation and viability in a dose dependent fashion. Compared with LFP-20, 25 to 200 μg/mL LF-l improved significantly cell proliferation ( P ＜ 0. 05) , while 400 μg/mL LF-1 decreased cell proliferation ( P ＜0. 05) . Both 200 and 400 μg/mL LF-1 induced an increase in lactate dehydrogenase ( LDH) release from PBMC (P ＜0. 05) whereas 25 to 50 μg/mL decreased the LDH release (P ＜0. 05). Moreover, LF-3 exhibited obviously enhanced potential to depolarize the cytoplasmic membranes at relatively low concentrations (4 μg/mL) . In contrast, LFP-20 and LF2A had more modest antibacterial activities, and a weaker ability to depolarize the cytoplasmic membrane. In conclusion, the antimicrobial activity of LF-3 is found to be 2 to 4 folds higher than that of LFP-20, which dose not couple with increased heomolysis and cytotoxicity to PBMCs. Moreover, LF-3 can disrupt the membrane potential by depolarizing the bacterial membrane, which is proposed to be one of the mechanisms of action of LF-3 . [ Chinese Journal of Animal Nutrition ,2011 ,23( 2 ) :241-249 ]关键词
猪/乳铁蛋白肽/抗菌活性/溶血性/细胞毒性分类
农业科技引用本文复制引用
韩菲菲,安沙,谢永刚,刘倚帆,汪以真..猪乳铁蛋白肽的分子改良及改良肽的生物学活性研究[J].动物营养学报,2011,23(2):241-249,9.基金项目
国家高技术研究发展计划(2007AA100602)、高等学校全国优秀博士学位论文作者专项资金资助项目(2007B6)资助 （2007AA100602）
