Structure-Reactivity Effects on Intrinsic Primary Kinetic Isotope Effects for Hydride Transfer Catalyzed by Glycerol-3-phosphate Dehydrogenase.

ABSTRACT: Primary deuterium kinetic isotope effects (1°DKIE) on (k_cat/K_GA, M^-1 s^-1) for dianion (X^2-) activated hydride transfer from NADL to glycolaldehyde (GA) catalyzed by glycerol-3-phosphate dehydrogenase were determined over a 2100-fold range of enzyme reactivity: (X^2-, 1°DKIE); FPO₃^2-, 2.8 ± 0.1; HPO₃^2-, 2.5 ± 0.1; SO₄^2-, 2.8 ± 0.2; HOPO₃^2-, 2.5 ± 0.1; S₂O₃^2-, 2.9 ± 0.1; unactivated; 2.4 ± 0.2. Similar 1°DKIEs were determined for k_cat. The observed 1°DKIEs are essentially independent of changes in enzyme reactivity with changing dianion activator. The results are consistent with (i) fast and revers

SUBMITTER: Reyes AC 

PROVIDER: S-EPMC5105681 | biostudies-literature | 2016 Nov

REPOSITORIES: biostudies-literature