title: S6 peptide derived from KvAP channel shows cooperativity in gating on bilayer lipid membrane.
abstract: Collective behavior of S6 peptide channels derived from KvAP (a bacterial potassium channel) incorporated in lipid bilayer membrane, has been investigated at various applied potentials through multi-channel electrophysiological experiments. The current versus time traces at any particular membrane potential show clear steps for sequential opening of the multi-channels. The minimum current (representing one-channel current) was found out from the amplitude histograms. Accordingly, the number of open channels corresponding to a particular open state was calculated. It was observed that the above-mentioned one channel current is higher than the corresponding single-channel current at most of the applied membrane potentials. Moreover, the difference between the single and one channel conductances is a nonlinear function of the membrane potential. We conclude that the S6 multi-channels show co-operative gating. Voltage relaxation studies support the above-mentioned conclusion.
authors.affiliation: Department of Biophysics, University of Delhi South Campus, New Delhi, India.
authors.forename: Chetan
authors.initials: C
authors.lastname: Malik
authors.forename: Subhendu
authors.initials: S
authors.lastname: Ghosh
mesh_terms: D001426:Bacterial Proteins; D002308:Cardiolipins / Q000378:metabolism; D015640:Ion Channel Gating; D008051:Lipid Bilayers / Q000378:metabolism*; D008564:Membrane Potentials; D010446:Peptide Fragments / Q000378:metabolism*; D015221:Potassium Channels / Q000737:chemistry / Q000378:metabolism*
chemical_list: D001426:Bacterial Proteins; D002308:Cardiolipins; D008051:Lipid Bilayers; D010446:Peptide Fragments; D015221:Potassium Channels