Viljanen P, Koski P, Vaara M
National Public Health Institute, Helsinki, Finland.
Infect Immun. 1988 Sep;56(9):2324-9. doi: 10.1128/iai.56.9.2324-2329.1988.
Defensins are small cationic antibacterial peptides that are abundant in polymorphonuclear leukocytes from human and other sources (T. Ganz, M. Selsted, D. Szklarek, S. Harwig, K. Daher, D. F. Bainton, and R. J. Lehrer, J. Clin. Invest. 76:1427-1435, 1985). We studied whether subinhibitory concentrations of defensins increase the outer membrane (OM) permeability of Escherichia coli, Salmonella typhimurium, and Pseudomonas aeruginosa to hydrophobic probes, as do many other polycations that have been studied previously. Throughout the study, we used polymyxin B nonapeptide (PMBN) as a reference peptide. PMBN has a known potent OM permeability-increasing action. As a sharp contrast to PMBN, subinhibitory concentrations of defensins did not permeabilize (or, under some test conditions, permeabilized very slightly) the OM to the probes that were used (rifampin and Triton X-100). At bacteriostatic or bactericidal defensin concentrations, some degree of synergism with rifampin was seen.
防御素是一类小的阳离子抗菌肽，在人和其他来源的多形核白细胞中含量丰富（T. 甘茨、M. 塞尔斯特德、D. 斯克拉雷克、S. 哈维格、K. 达赫尔、D. F. 班顿和R. J. 莱勒，《临床研究杂志》76:1427 - 1435，1985年）。我们研究了亚抑制浓度的防御素是否会像之前研究过的许多其他聚阳离子一样，增加大肠杆菌、鼠伤寒沙门氏菌和铜绿假单胞菌外膜（OM）对疏水探针的通透性。在整个研究过程中，我们使用多粘菌素B九肽（PMBN）作为参考肽。PMBN具有已知的强大的增加外膜通透性的作用。与PMBN形成鲜明对比的是，亚抑制浓度的防御素并未使外膜对所使用的探针（利福平和 Triton X - 100）产生通透性（或者在某些测试条件下，通透性非常轻微）。在抑菌或杀菌浓度的防御素下，观察到与利福平有一定程度的协同作用。
