The effect of protein dielectric coefficient on the ionic selectivity of a calcium channel

摘要: Calcium-selective ion channels are known to have carboxylate-rich selectivity filters, a common motif that is primarily responsible for their high Ca2+ affinity. Different affinities ranging from micromolar (the L-type Ca channel) millimolar ryanodine receptor closely related the different physiological functions of these channels. To understand physical mechanism this range given similar amino acids in we use grand canonical Monte Carlo simulations assess binding monovalent and divalent ions filter model channel. We reduced where electolyte modeled by hard-sphere embedded continuum dielectric solvent, while interior protein surrounding channel allowed coefficient electrolyte. The induced charges appear on protein/lumen interface calculated charge computation method [Boda et ...