Role of Internal Water on Protein Thermal Stability: The Case of Homologous G Domains.

ABSTRACT: In this work, we address the question of whether the enhanced stability of thermophilic proteins has a direct connection with internal hydration. Our model systems are two homologous G domains of different stability: the mesophilic G domain of the elongation factor thermal unstable protein from E. coli and the hyperthermophilic G domain of the EF-1α protein from S. solfataricus. Using molecular dynamics simulation at the microsecond time scale, we show that both proteins host water molecules in internal cavities and that these molecules exchange with the external solution in the nanosecond time scale. The hydration free energy of these sites evaluated via extensive calculations is found to be favorable for both systems, with the hyperthermophilic protein offering a slightly more favorable

SUBMITTER: Rahaman O 

PROVIDER: S-EPMC4762204 | biostudies-literature | 2015 Jul

REPOSITORIES: biostudies-literature