Understanding Substrate Unbinding from the Sodium-Galactose Co-Transporter vSGLT based on 16 Microseconds of Molecular Simulation


We report the results from 16 microseconds of molecular dynamics (MD) simulations carried out on vSGLT using the Anton supercomputer at the Pittsburgh Supercomputing Center. We observed multiple galactose unbinding events as well as instances in which the energizing sodium ion unbind and then rebind to the putative sodium binding site. Using umbrella sampling we calculated the potential of mean force (pmf) for all galactose unbinding trajectories. We will discuss the allosteric interaction between the ion and substrate and the potential for one to control the release of the other via the inner and outer gates.

Biophys. J.