Hai Lin of the University of Colorado at Denver is supported by a CAREER award from the Theory, Models and Computational Methods program to carry out multiscale simulations of chloride transport proteins by combined quantum and classical mechanical approaches. The Molecular and Cell Biology division also contributes to this award in a co-funding arrangement. The research focuses on understanding the gating, selectivity and permeation of the Cl- and Cl-/H+ exchangers. In particular, Lin and coworkers are investigating how quantum effects, such as charge transfer and tunneling, tune the mechanism and the underlying dynamics of ion translocation. In order to perform these calculations, they are further developing the open boundary QM/MM method. Unlike conventional QM/MM methods, the open boundary method permits the quantum and classical subsystems to exchange atoms and charges on the fly in dynamic simulations, making it very suitable for the study of ion transport.
The ClC chloride transport proteins have been found to be associated with a variety of critical physiological and cellular processes such as neuroexcitation, cell-volume regulation, organic solute transport and muscle contraction. Defects in these channels lead to a variety of hereditary diseases
