Naranjo, DMoldenhauer, HPincuntureo, MDiaz-Franulic, I2017-04-282017-04-282016-10Journal of General Physiology 148(4),2770022-1295DOI: 10.1085/jgp.201611625http://repositorio.unab.cl/xmlui/handle/ria/3358Indexación: Web of Science; Scopus; Scielo.Ion channels are membrane proteins that mediate efficient ion transport across the hydrophobic core of cell membranes, an unlikely process in their absence. K+ channels discriminate K+ over cations with similar radii with extraordinary selectivity and display a wide diversity of ion transport rates, covering differences of two orders of magnitude in unitary conductance. The pore domains of large- and small-conductance K+ channels share a general architectural design comprising a conserved narrow selectivity filter, which forms intimate interactions with permeant ions, flanked by two wider vestibules toward the internal and external openings. In large- conductance K+ channels, the inner vestibule is wide, whereas in small-conductance channels it is narrow. Here we raise the idea that the physical dimensions of the hydrophobic internal vestibule limit ion transport in K+ channels, accounting for their diversity in unitary conductance.enSHAKER K+ CHANNELLONG QT SYNDROMEQUATERNARY AMMONIUM BLOCKERSBK CHANNELSION SELECTIVITYMOLECULAR-DYNAMICSPERMEATION PATHWAYSTRUCTURAL BASISACTIVATION GATEVOLTAGE SENSORArtículo