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001-es BibID:	BIBFORM004739
Első szerző:	Starkus, John G.
Cím:	Mechanisms of the inhibition of Shaker potassium channels by protons / John G. Starkus, Zoltán Varga, Roland Schönherr, Stefan H. Heinemann
Dátum:	2003
ISSN:	0031-6768
Megjegyzések:	Potassium channels are regulated by protons in various ways and, in most cases, acidification results in potassium current reduction. To elucidate the mechanisms of proton-channel interactions we investigated N-terminally truncated Shaker potassium channels (Kv1 channels) expressed in Xenopus oocytes, varying pH at the intracellular and the extracellular face of the membrane. Intracellular acidification resulted in rapid and reversible channel block. The block was half-maximal at pH 6.48, thus even physiological excursions of intracellular pH will have an impact on K+ current. The block displayed only very weak voltage dependence and C-type inactivation and activation were not affected. Extracellular acidification (up to pH 4) did not block the channel, indicating that protons are effectively excluded from the selectivity filter. Channel current, however, was reduced greatly due to marked acceleration of C-type inactivation at low pH. In contrast, inactivation was not affected in the T449V mutant channel, in which C-type inactivation is impaired. The pH effect on inactivation of the wild-type channel had an apparent pK of 4.7, suggesting that protonation of extracellular acidic residues in Kv channels makes them subject to pH regulation
Tárgyszavak:	Orvostudományok Elméleti orvostudományok idegen nyelvű folyóiratközlemény külföldi lapban Animals Comparative Study drug effects Female Ion Channel Gating Oocytes pharmacology physiology Potassium Potassium Channel Blockers Potassium Channels Protons Research Shaker Superfamily of Potassium Channels Support Xenopus
Megjelenés:	Pflügers Archiv. - 447 : 1 (2003), p. 44-54. -
További szerzők:	Varga Zoltán (1969-) (biofizikus, szakfordító) Schönherr, Roland Heinemann, Stefan H.
Internet cím:	Intézményi repozitóriumban (DEA) tárolt változat DOI
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