Yeast alcohol dehydrogenase catalyzed reduction of p-nitroso-N, N-dimethylaniline by NADH
Leskovac, V.; Trivic, S.; Anderson, B.M.
Italian Journal of Biochemistry 45(1): 9-18
1996
ISSN/ISBN: 0021-2938 PMID: 8930732 Document Number: 462220
The steady-state kinetics, product identification, stoichiometries, and solvent isotope effects of yeast alcohol dehydrogenase catalyzed reduction of p-nitroso-N,N-dimethylaniline (NDMA) by NADH, are reported. NDMA is enzymatically reduced to p-hydroxylamine-N,N-dimethylaniline, which is further enzymatically dehydrated to corresponding quinonediimine cation (QDI+). QDI+ undergoes nonenzymatic transformations. QDI+ is rapidly reduced by NADH to p-amino-N,N-dimethylaniline (ADMA). Also, QDI+ is readily dismutated with ADMA to form N,N-dimethyl-p-phenylenediamine radicals; radicals are stable under steady-state conditions, below pH 7.5. A complete kinetic mechanism for above reactions has been proposed.