Magainin 2 revisited: a test of the quantitative model for the all-or-none permeabilization of phospholipid vesicles.

摘要: The all-or-none kinetic model that we recently proposed for the antimicrobial peptide cecropin A is tested here magainin 2. In mixtures of phosphatidylcholine (PC)/phosphatidylglycerol (PG) 50:50 and 70:30, release contents from lipid vesicles occurs in an fashion differences between PC/PG 70:30 can be ascribed mainly to binding, which was determined independently ∼20 times greater than 70:30. Only one variable parameter, β, corresponding ratio rates pore opening closing, used fit dye kinetics these two mixtures, several peptide/lipid ratios ranging 1:25 1:200. However, unlike where it stays almost constant, β increases five as PG content 30 50%. Thus, 2 more sensitive anionic A. But overall, follows same with slightly different parameter values. When reduced 20 mol %, becomes very low; mechanism appears change, consistent a graded model. We suggest may inducing formation domains. either mechanism, no oligomerization catalyzes proportion its concentration on membrane state call pore. envision this structure chaotic or stochastic type pore, involving both lipids peptides, not well-defined, peptide-lined channel.