Effect of agents modifying the membrane dipole potential on properties of syringomycin E channels

Langmuir. 2007 Jun 19;23(13):6889-92. doi: 10.1021/la7005452. Epub 2007 May 18.

Abstract

We evaluated the effect of agents modifying the membrane dipole potential: phloretin, 6-ketocholestanol and RH 421 on the properties of single channels formed by lipodepsipeptide syringomycin E (SRE) in planar lipid bilayers. SRE forms two conductive states in lipid bilayers: "small" and "large." Large SRE channels are clusters of several small ones, demonstrating synchronous openings and closures. The increase in the membrane dipole potential led to (i) an increase in SRE channel conductance, (ii) an increase in the channel's lifetime, and (iii) a decrease in a number of synchronously operating small channels in the clusters. Overall, the results support the model of the small SRE channel synchronization in the cluster as voltage-dependent orientation of the lipid dipoles associated with the channel pores.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Ketocholesterols / chemistry*
  • Membrane Potentials
  • Membranes, Artificial*
  • Models, Chemical*
  • Peptides, Cyclic / chemistry*
  • Phloretin / chemistry*
  • Pyridinium Compounds / chemistry*
  • Styrenes / chemistry*

Substances

  • Ketocholesterols
  • Membranes, Artificial
  • Peptides, Cyclic
  • Pyridinium Compounds
  • Styrenes
  • RH 421
  • syringomycin E
  • 6-ketocholestanol
  • Phloretin