Dynamic Characteristics of Guanosine-5'-monophosphate Reductase Complexes Revealed by High-Resolution ³¹P Field-Cycling NMR Relaxometry.

ABSTRACT: The ability of enzymes to modulate the dynamics of bound substrates and cofactors is a critical feature of catalysis, but the role of dynamics has largely been approached from the perspective of the protein. Here, we use an underappreciated NMR technique, subtesla high-resolution field-cycling ³¹P NMR relaxometry, to interrogate the dynamics of enzyme bound substrates and cofactors in guanosine-5'-monophosphate reductase (GMPR). These experiments reveal distinct binding modes and dynamic profiles associated with the ³¹P nuclei in the Michaelis complexes for the deamination and hydride transfer steps of the catalytic cycle. Importantly, the substrate is constrained and the cofactor is more dynamic in the deamination complex E·GMP·NADP⁺, whereas the substrate

SUBMITTER: Rosenberg MM 

PROVIDER: S-EPMC6467290 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature