Protein mass-modulated effects in the catalytic mechanism of dihydrofolate reductase: beyond promoting vibrations.

ABSTRACT: The role of fast protein dynamics in enzyme catalysis has been of great interest in the past decade. Recent "heavy enzyme" studies demonstrate that protein mass-modulated vibrations are linked to the energy barrier for the chemical step of catalyzed reactions. However, the role of fast dynamics in the overall catalytic mechanism of an enzyme has not been addressed. Protein mass-modulated effects in the catalytic mechanism of Escherichia coli dihydrofolate reductase (ecDHFR) are explored by isotopic substitution ((13)C, (15)N, and non-exchangeable (2)H) of the wild-type ecDHFR (l-DHFR) to generate a vibrationally perturbed "heavy ecDHFR" (h-DHFR). Steady-state, pre-steady-state, and ligand binding kinetics, intrinsic kinetic isotope effects (KIEint) on the chemical step, and thermal unfoldi

SUBMITTER: Wang Z 

PROVIDER: S-EPMC4063187 | biostudies-literature | 2014 Jun

REPOSITORIES: biostudies-literature