Ground-state electronic destabilization via hyperconjugation in aspartate aminotransferase.

ABSTRACT: Binding isotope effects for l-aspartate reacting with the inactive K258A mutant of PLP-dependent aspartate aminotransferase to give a stable external aldimine intermediate are reported. They provide direct evidence for electronic ground-state destabilization via hyperconjugation. The smaller equilibrium isotope effect with deazaPLP-reconstituted K258A indicates that the pyridine nitrogen plays an important role in labilizing the Cα-H bond.

SUBMITTER: Griswold WR 

PROVIDER: S-EPMC3425665 | biostudies-literature | 2012 May

REPOSITORIES: biostudies-literature