Quantitative, directional measurement of electric field heterogeneity in the active site of ketosteroid isomerase.

ABSTRACT: Understanding the electrostatic forces and features within highly heterogeneous, anisotropic, and chemically complex enzyme active sites and their connection to biological catalysis remains a longstanding challenge, in part due to the paucity of incisive experimental probes of electrostatic properties within proteins. To quantitatively assess the landscape of electrostatic fields at discrete locations and orientations within an enzyme active site, we have incorporated site-specific thiocyanate vibrational probes into multiple positions within bacterial ketosteroid isomerase. A battery of X-ray crystallographic, vibrational Stark spectroscopy, and NMR studies revealed electrostatic field heterogeneity of 8 MV/cm between active site probe locations and widely differing sensitivities of discr

SUBMITTER: Fafarman AT 

PROVIDER: S-EPMC3277571 | biostudies-literature | 2012 Feb

REPOSITORIES: biostudies-literature