Temporal and spatial resolution of distal protein motions that activate hydrogen tunneling in soybean lipoxygenase.

ABSTRACT: The enzyme soybean lipoxygenase (SLO) provides a prototype for deep tunneling mechanisms in hydrogen transfer catalysis. This work combines room temperature X-ray studies with extended hydrogen-deuterium exchange experiments to define a catalytically-linked, radiating cone of aliphatic side chains that connects an active site iron center of SLO to the protein-solvent interface. Employing eight variants of SLO that have been appended with a fluorescent probe at the identified surface loop, nanosecond fluorescence Stokes shifts have been measured. We report a remarkable identity of the energies of activation (E_a) for the Stokes shifts decay rates and the millisecond C-H bond cleavage step that is restricted to side chain mutants within an identified thermal network. These f

SUBMITTER: Zaragoza JPT 

PROVIDER: S-EPMC10013837 | biostudies-literature | 2023 Mar

REPOSITORIES: biostudies-literature