Hancock R E, Wong P G
Antimicrob Agents Chemother. 1984 Jul;26(1):48-52. doi: 10.1128/AAC.26.1.48.
Hydrolysis of the chromogenic beta-lactam nitrocefin by periplasmic beta-lactamase in intact Pseudomonas aeruginosa cells was used to assess the influence of various compounds on the permeability of the P. aeruginosa outer membrane. In addition to the five previously described outer membrane-active compounds EDTA, polymyxin B, gentamicin, poly-L-lysine, and Tris, seven other compounds were shown to increase outer membrane permeability to nitrocefin by 14- to 63-fold. These other compounds included poly-L-ornithine, neomycin, cetyltrimethylammonium bromide, nitrilotriacetate, L-ascorbate, and acetylsalicylate. In each case, Mg2+ ions antagonized, to different extents, the enhancement of outer membrane permeability. The same compounds increased the permeability of the outer membrane to the protein lysozyme and to the hydrophobic fluorescent probe 1-N-phenylnaphthylamine, although L-ascorbate and acetylsalicylate showed only very weak enhancement of uptake in these assays. In this report, we discuss the possibility that these compounds act at a common outer membrane site at which divalent cations noncovalently cross-bridge adjacent lipopolysaccharide molecules.
完整的铜绿假单胞菌细胞中周质β-内酰胺酶对显色β-内酰胺硝基头孢菌素的水解作用，被用于评估各种化合物对铜绿假单胞菌外膜通透性的影响。除了之前描述的五种外膜活性化合物——乙二胺四乙酸（EDTA）、多粘菌素B、庆大霉素、聚-L-赖氨酸和三羟甲基氨基甲烷（Tris）外，其他七种化合物也被证明可使外膜对硝基头孢菌素的通透性提高14至63倍。这些其他化合物包括聚-L-鸟氨酸、新霉素、十六烷基三甲基溴化铵、次氮基三乙酸、L-抗坏血酸盐和乙酰水杨酸酯。在每种情况下，镁离子都不同程度地拮抗外膜通透性的增强。相同的化合物也增加了外膜对蛋白质溶菌酶和疏水荧光探针1-N-苯基萘胺的通透性，尽管在这些实验中L-抗坏血酸盐和乙酰水杨酸酯仅表现出非常微弱的摄取增强作用。在本报告中，我们讨论了这些化合物可能作用于一个共同的外膜位点的可能性，在该位点二价阳离子以非共价方式跨桥相邻的脂多糖分子。
