title: Tyrosinase inactivation in its action on dopa.
abstract: Under aerobic or anaerobic conditions, tyrosinase undergoes a process of irreversible inactivation induced by its physiological substrate L-dopa. Under aerobic conditions, this inactivation occurs through a process of suicide inactivation involving the form oxy-tyrosinase. Under anaerobic conditions, both the met- and deoxy-tyrosinase forms undergo irreversible inactivation. Suicide inactivation in aerobic conditions is slower than the irreversible inactivation under anaerobic conditions. The enzyme has less affinity for the isomer D-dopa than for L-dopa but the velocity of inactivation is the same. We propose mechanisms to explain these processes.
authors.affiliation: GENZ: Grupo de Investigación Enzimología, Departamento de Bioquímica y Biología Molecular-A, Facultad de Biologia, Universidad de Murcia, E-30100, Espinardo, Murcia, Spain.
authors.forename: J L
authors.initials: JL
authors.lastname: Muñoz-Muñoz
authors.forename: J R
authors.initials: JR
authors.lastname: Acosta-Motos
authors.forename: F
authors.initials: F
authors.lastname: Garcia-Molina
authors.forename: R
authors.initials: R
authors.lastname: Varon
authors.forename: P A
authors.initials: PA
authors.lastname: Garcia-Ruíz
authors.forename: J
authors.initials: J
authors.lastname: Tudela
authors.forename: F
authors.initials: F
authors.lastname: Garcia-Cánovas
authors.forename: J N
authors.initials: JN
authors.lastname: Rodríguez-López
mesh_terms: D000363:Agaricales / Q000201:enzymology; D002384:Catalysis; D020134:Catalytic Domain; D004156:Catechol Oxidase / Q000737:chemistry; D004295:Dihydroxyphenylalanine / Q000737:chemistry*; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D008954:Models, Biological; D008956:Models, Chemical; D014442:Monophenol Monooxygenase / Q000737:chemistry*; D010100:Oxygen / Q000737:chemistry; D011485:Protein Binding; D013053:Spectrophotometry / Q000379:methods; D013997:Time Factors
chemical_list: D004295:Dihydroxyphenylalanine; D004156:Catechol Oxidase; D014442:Monophenol Monooxygenase; D010100:Oxygen