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Published on: December 7, 2015
5- and 4'-Hydroxylated flavonoids affect voltage gating of single alpha-hemolysin pore
Olga S Ostroumova1, Svetlana S Efimova, Ludmila V Schagina
1Institute of Cytology of the Russian Academy of Sciences, St. Petersburg 194064, Russia. ostroumova@mail.cytspb.rssi.ru
Abstract:
Molecular mechanisms of the influence of flavonoids on the voltage gating of a single alpha-hemolysin channel in planar lipid membranes are studied. It is shown that the addition of flavonoids hydroxylated in position 5 of the A-ring and in position 4' of the B-ring into bilayer bathing solution shifts the voltage dependence of channel switching from high- to low-conductance states to voltages nearer zero. It is concluded that the effect is likely to be attributed to a specific interaction of at least three flavonoid molecules with the voltage sensor of an alpha-hemolysin pore. Possible flavonoid binding sites and identification of amino acid residues included into the voltage sensor domain of the alpha-hemolysin channel are discussed.
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