Citation

Garcia-Molina F, Munoz-Munoz JL, Garcia-Molina M, Garcia-Ruiz PA, Tudela J, García-Cánovas F, Rodriguez-Lopez JN. Biosci. Biotechnol. Biochem. 2010; 74(9): 1777-1787.

Copyright

(Copyright © 2010, Japan Society for Bioscience, Biotechnology, and Agrochemistry)

DOI

10.1271/bbb.90965

PMID

20834177

Abstract

The effect of NADH on melanogenesis under aerobic conditions involves three types of reaction: (a) acting as tyrosinase substrate (a competitive substrate of L-tyrosine and L-DOPA), (b) irreversible inactivation acting as a suicide substrate of tyrosinase, and (c) non-enzymatic reduction of o-dopaquinone by NADH. Under anaerobic conditions, NADH irreversibly inhibits the enzymatic forms met-tyrosinase and deoxy-tyrosinase. In this paper, we kinetically characterize this coenzyme as it acts as a tyrosinase suicide substrate and propose a kinetic mechanism to explain its oxidation by tyrosinase. In addition, the compound is characterized as an irreversible inhibitor of met-tyrosinase and deoxy-tyrosinase.

Language: en

Keywords

Kinetics; Oxidation-Reduction; Substrate Specificity; Fungal Proteins; Agaricales; Indoles; Dihydroxyphenylalanine; NAD; Monophenol Monooxygenase; Benzoquinones; Melanins