t-butyl hydrogen peroxide가 쥐 뇌의 Ca2+-activated K+ channel(Maxi-K)에 미치는 영향

초록

Oxidation and reduction of amino acid residues in proteins affect their functional properties. Especially, redox modulation of ion channel activities has been reported in number of ion channel proteins. However, the mechanism of redox modulation is not yet known at molecular level. t-Butyl hydrogen peroxide (tBHP) is an analogue of H2O2, and the target for oxidation by tBHP and H2O2 is suggested to be methionine (Met) residue. Interestingly, the oxidation pattern of tBHP is reported to be different with the one by H2O2. While tBHP selectively oxidizes the Met residues exposed on the surface of target protein, H2O2 oxidizes the Met residues buried in the core of protein as well as those exposed. In this study, we investigated the effects of tBHP on the large-conductance Ca2+-activated K+ (Maxi-K) channel of rat brain. The specific aims of this study are to investigate whether differential effects on maxi-K channel activities can be observed between different oxidants and to explain the redox modulation at molecular level.