Analysis of the kinetic mechanism of enterococcal NADH peroxidase reveals catalytic roles for NADH complexes with both oxidized and two-electron-reduced enzyme forms

A study using kinetic and spectroscopic techniques was conducted to examine the kinetic mechanism of the catalytic activity of NADH peroxidase derived from Enterococcus faecalis. The results show that the catalytic mechanism involves rapid formation of a complex of oxidized enzyme and NADH, a rate-limiting hydride transfer step that produces two-electron-reduced NADH peroxidase and rapid formation of an NADH peroxidase-NADH intermediate.