Cui, Dachao; Ren, Weitong; Li, Wenfei; Wang, Wei
Molecular simulations of substrate release and coupled conformational motions in adenylate kinase
JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY, 15 Art. No. 1650004, FEB 2016

Conformational opening coupled substrate release is believed to be related to the rate limiting step in the catalysis cycle of the adenylate kinase. However, it is still unclear how the substrate dissociates from its active site and how the substrate release is coupled to conformational changes of the kinase. In this work, by using metadynamics simulations, we investigated the ADP release process and the coupled protein dynamics. We found that the ADP release involves overcoming a high free energy barrier, and protonation of the beta-phosphate of the ADP molecules can drastically reduce the barrier height, therefore, promote the ADP release. We identified several key residues contributing to the high free energy barrier. We also showed that the ADP attached to LID domain leaves the binding pocket earlier than the one attached to the NMP domain. We further observed that the ADP release is accompanied by almost fully opening of the LID domain and partially opening of the NMP domain. Our results provide insight into the molecular mechanism of the substrate release of adenylate kinase and the coupled conformational motions.

DOI:10.1142/S0219633616500048

Find full text with Google Scholar.