Abstract
Calcium-selective ion channels often contain a selectivity filter made of similar amino acids, rich in carboxlylates, although the affinities of these channels range from micromolar to millimolar. To understand the physical mechanism for this range of affinities, we use grand canonical Monte Carlo simulations to study the competition of and in the selectivity filter of a reduced model of a Ca channel. We show that affinity is increased dramatically when both the volume and dielectric coefficient of the protein are reduced.
- Received 28 August 2006
DOI:https://doi.org/10.1103/PhysRevLett.98.168102
©2007 American Physical Society