title: 5- and 4'-Hydroxylated flavonoids affect voltage gating of single alpha-hemolysin pore.
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.
authors.affiliation: Institute of Cytology of the Russian Academy of Sciences, St. Petersburg 194064, Russia. ostroumova@mail.cytspb.rssi.ru
authors.forename: Olga S
authors.initials: OS
authors.lastname: Ostroumova
authors.forename: Svetlana S
authors.initials: SS
authors.lastname: Efimova
authors.forename: Ludmila V
authors.initials: LV
authors.lastname: Schagina
mesh_terms: D001427:Bacterial Toxins / Q000737:chemistry / Q000378:metabolism; D001665:Binding Sites; D002462:Cell Membrane / Q000737:chemistry*; D005419:Flavonoids / Q000737:chemistry / Q000378:metabolism / Q000494:pharmacology*; D006460:Hemolysin Proteins / Q000737:chemistry / Q000187:drug effects* / Q000378:metabolism; D006900:Hydroxylation; D015640:Ion Channel Gating / Q000187:drug effects*; D008563:Membrane Lipids / Q000737:chemistry*; D008564:Membrane Potentials; D008567:Membranes, Artificial; D015394:Molecular Structure; D013329:Structure-Activity Relationship
chemical_list: D001427:Bacterial Toxins; D005419:Flavonoids; D006460:Hemolysin Proteins; D008563:Membrane Lipids; D008567:Membranes, Artificial; C021091:staphylococcal alpha-toxin