Altering channel forming activity of syringomycin E via membrane dipole potential
Ostroumova O.S., Malev V.V., Bessonov A.N., Takemoto J.Y., Schagina L.V
The membrane dipole potential is responsible for the modulation of numerous biological processes. It was previously shown (Ostroumova, O. S.; Kaulin, Y. A.; Gurnev, P. A.; Schagina, L. V. Langmuir 2007, 23, 6889-6892) that variations in the dipole potential lead to changes in the channel properties of the antifungal lipodepsipeptide syringomycin E (SRE). Here, data are presented demonstrating the effect of the membrane dipole potential on the channel-forming activity of SRE. A rise in the dipole potential is accompanied by both an increase in the minimum SRE concentration required for the detection of single channels at fixed voltage and a decrease in the steady-state number of open SRE channels at a given SRE concentration and voltage. These alterations are determined by several factors: gating charge, connected with translocations of lipid and SRE dipoles during channel formation, the bilayer-water solution partitioning of SRE, and the chemical work related to conformational changes during channel formation.
Ostroumova O.S., Malev V.V., Bessonov A.N., Takemoto J.Y., Schagina L.V. 2008. Altering channel forming activity of syringomycin E via membrane dipole potential. Langmuir 24: 2987-2991