Altering the activity of syringomycin E via the membrane dipole potential.
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
Olga S
OS
Institute of Cytology of the Russian Academy of Sciences, St. Petersburg 194064, Russia. ostroumova@mail.cytspb.rssi.ru
Malev
Valery V
VV
Bessonov
Andrey N
AN
Takemoto
Jon Y
JY
Schagina
Ludmila V
LV
D000935:Antifungal Agents / Q000494:pharmacology; D002463:Cell Membrane Permeability / Q000187:drug effects; D004594:Electrophysiology; D008051:Lipid Bilayers; D008564:Membrane Potentials / Q000502:physiology*; D010456:Peptides, Cyclic / Q000494:pharmacology*
D000935:Antifungal Agents; D008051:Lipid Bilayers; D010456:Peptides, Cyclic; C105246:syringomycin E