Structural Effects on the Hydride-Tunneling Kinetic Isotope Effects of NADH/NAD⁺ Model Reactions: Relating to the Donor-Acceptor Distances.

ABSTRACT: Contemporary H-tunneling theories predict that a longer donor-acceptor distance (DAD) corresponds to a larger kinetic isotope effect (KIE). Herein, hydride-tunneling reactions of NADH/NAD⁺ analogues in acetonitrile were used to examine the KIE-DAD relationship. Reaction pairs of similar tunneling-ready conformations were selected, so that additional factors influencing KIEs would be relatively fixed. Positive results were obtained, with some reaction pairs displaying a reversal of the traditional KIE-ΔG° relationship in favor of the KIE-DAD relationship, lending strong support to the latter.

SUBMITTER: Austin A 

PROVIDER: S-EPMC11877500 | biostudies-literature | 2025 Feb

REPOSITORIES: biostudies-literature