Solvent site-dipole Fields around Guanine Nucleotides in the Hras-GTP Complex and in the Hras-GDP Complex

摘要

Directional correlation of solvent site-dipole field, resulting from orientational ordering of individual water molecules around guanine nucleotides in the Hras-GTP complex and in the Hras-GDP complex, was studied with molecular dynamics simulations of the Hras-GTP and the Hras-GDP complexes in water solution. The coarse-grained time-window-averaged site-dipole fields are different between Hras-GTP and Hras-GDP at some area, although the time-window-averaged site-dipole fields without spatial coarse-graining are not so different. This suggests that, for the orientation of water molecules at special position, the spatial coherence is more important than the temporal coherence for GTP hydrolysis in the Hras-GTP complex.