Understanding Biological Hydrogen Transfer Through the Lens of Temperature Dependent Kinetic Isotope Effects.

ABSTRACT: Hydrogen atom transfer (HAT) is a salient feature of many enzymatic C-H cleavage mechanisms. In systems where kinetic isolation of HAT is achieved, selective labeling of substrate with hydrogen isotopes, such as deuterium, enables the determination of intrinsic kinetic isotope effects (KIEs). While the magnitude of the KIE is itself informative, ultimately the size of the temperature dependence of the KIE, Δ E_a = E_a(D) - E_a(H), serves as a critical, and often misinterpreted (or even ignored) descriptor of the reaction coordinate. As will be highlighted in this Account, Δ E_a is one of the most robust parameters to emerge from studies of enzyme catalyzed hydrogen transfer. Kinetic parameters for C-H reactions via HAT can appear consistent with eith

SUBMITTER: Klinman JP 

PROVIDER: S-EPMC6258190 | biostudies-literature | 2018 Sep

REPOSITORIES: biostudies-literature