Cluster Organization of Ion Channels Formed by the Antibiotic Syringomycin E in Bilayer Lipid Membranes

摘要: The cyclic lipodepsipeptide, syringomycin E, when incorporated into planar lipid bilayer membranes, forms two types of channels (small and large) that are different in conductance by a factor sixfold. To discriminate between cluster organization-type channel structure other possible structures for the types, their ionic selectivity pore size were determined. Pore was assessed using water-soluble polymers. Ion found to be essentially same both small large channels. Their reversal (zero current) potentials with sign corresponding anionic did not differ more than 3 mV at twofold electrolyte gradient across bilayer. Reduction single-channel induced poly(ethylene glycol)s molecular weights demonstrated aqueous sizes 2% close 1 nm. Based on virtually identical size, we conclude E clusters ones exhibiting synchronous opening closing.