Select Configurational Dynamics in Ethanolamine Ammonia-Lyase Radical Enzyme Catalysis.

ABSTRACT: Contributions of protein and coupled solvent configurational fluctuations to the molecular mechanism of enzyme catalysis are addressed in the adenosylcobalamin (coenzyme B₁₂)-dependent ethanolamine ammonia-lyase (EAL) enzyme from Salmonella enterica serovar Typhimurium. Full-spectrum, time-resolved electron paramagnetic resonance (EPR) spectroscopy is used to measure the temperature dependence of the first-order kinetics of the substrate radical reaction in EAL surrounded by successive hydration and aqueous-cosolvent (aminoethanol; added dimethyl sulfoxide, glycerol, and sucrose) layers in frozen solution. At different temperature (T) values in each system, the piecewise-continuous Arrhenius relation displays the characteristic bifurcation, from high-T monoe

SUBMITTER: Li W 

PROVIDER: S-EPMC12670283 | biostudies-literature | 2025 Nov

REPOSITORIES: biostudies-literature