Voltage-dependent synchronization of gating of syringomycin E ion channels |
| |
Authors: | Ostroumova O S Malev V V Kaulin Yu A Gurnev Ph A Takemoto J Y Schagina L V |
| |
Affiliation: | Institute of Cytology of the Russian Academy of Sciences, St. Petersburg. |
| |
Abstract: | Antifungal lipodepsipeptide syringomycin E (SRE) forms two major conductive states in lipid bilayers: "small" and "large". Large SRE channels are cluster of several small ones, demonstrating synchronous opening and closure. To get insight into the mechanism of such synchronization we investigated how transmembrane potential, membrane surface charge, and ionic strength affect the number of small SRE channels synchronously functioning in the cluster. Here, we report that the large SRE channels can be presented as 3-8 simultaneously gating small channels. The increase in the absolute value of the transmembrane potential (from 50 to 200 mV) decreases the number of synchronously gated channels in the clusters. Voltage-dependence of channel synchronization was influenced by the ionic strength of the bathing solution, but not by membrane surface charge. We propose a mechanism for the voltage-dependent cluster behavior that involves a voltage-induced reorientation of lipid dipoles associated with the channel pores. |
| |
Keywords: | SRE, syringomycin E PC, 1,2-diphytanoyl-sn-glycero-3-phosphocholine PS, 1,2-dioleoyl-sn-glycero-3-phosphoserine PE, 1,2-dioleoyl-sn-glycero-3-phosphoethanolamine PS/PE, an equimolar mixture of PS and PE |
本文献已被 ScienceDirect PubMed 等数据库收录! |
|