Adenylate Kinase-Catalyzed Reaction of AMP in Pieces: Enzyme Activation for Phosphoryl Transfer to Phosphite Dianion.

ABSTRACT: The binding of adenosine 5'-triphosphate (ATP) and adenosine 5'-monophosphate (AMP) to adenylate kinase (AdK) drives closure of lids over the substrate adenosyl groups. We test the hypothesis that this conformational change activates AdK for catalysis. The rate constants for Homo sapiens adenylate kinase 1 (HsAdK1)-catalyzed phosphoryl group transfer to AMP, k_cat/K_m = 7.0 × 10⁶ M^-1 s^-1, and phosphite dianion, (k_HPi)_obs ≤1 × 10^-4 M^-1 s^-1, show that the binding energy of the adenosyl group effects a ≥7.0 × 10¹⁰-fold rate acceleration of phosphoryl transfer from ATP. The third-order rate constant of k_cat/K_HPi<

SUBMITTER: Fernandez PL 

PROVIDER: S-EPMC8436233 | biostudies-literature | 2021 Sep

REPOSITORIES: biostudies-literature