Ion selectivity and current saturation in inward-rectifier K+ channels
نویسندگان
چکیده
منابع مشابه
Ion selectivity and current saturation in inward-rectifier K+ channels
We investigated the features of the inward-rectifier K channel Kir1.1 (ROMK) that underlie the saturation of currents through these channels as a function of permeant ion concentration. We compared values of maximal currents and apparent K(m) for three permeant ions: K(+), Rb(+), and NH(4)(+). Compared with K(+) (i(max) = 4.6 pA and K(m) = 10 mM at -100 mV), Rb(+) had a lower permeability, a lo...
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Previous studies suggested that the cytoplasmic COOH-terminal portions of inward rectifier K channels could contribute significant resistance barriers to ion flow. To explore this question further, we exchanged portions of the COOH termini of ROMK2 (Kir1.1b) and IRK1 (Kir2.1) and measured the resulting single-channel conductances. Replacing the entire COOH terminus of ROMK2 with that of IRK1 de...
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ژورنال
عنوان ژورنال: Journal of General Physiology
سال: 2012
ISSN: 1540-7748,0022-1295
DOI: 10.1085/jgp.201110727