title: Characterization of the action of tyrosinase on resorcinols.
abstract: The action of tyrosinase on resorcinol and some derivatives (4-ethylresorcinol, 2-methylresorcinol and 4-methylresorcinol) was investigated. If the catalytic cycle is completed with a reductant such as ascorbic acid or an o-diphenol such as 4-tert-butylcatechol, these compounds act as substrates of tyrosinase in all cases. The reaction can also be carried out, adding hydrogen peroxide to the medium. All the above compounds were characterized as substrates of the enzyme and their kinetic constants, KM (Michaelis constant) and kcat (catalytic constant) were determined. Measurement of the activity of the enzyme after pre-incubation with resorcinol, 4-ethylresorcinol or 4-methylresorcinol points to an apparent loss of activity at short times, which could correspond to an enzymatic inactivation process. However, if the measurements are extended over longer times, a burst is observed and the enzymatic activity is recovered, demonstrating that these compounds are not suicide substrates of the enzyme. These effects are not observed with 2-methylresorcinol. The docking results indicate that the binding of met-tyrosinase with these resorcinols occurs in the same way, but not with 2-methylresorcinol, due to steric hindrance.
authors.affiliation: University of Murcia, Faculty of Veterinary, GENZ-Group of Research on Enzymology (www.um.es/genz), Department of Biochemistry and Molecular Biology-A, 30100 Murcia, Spain.
authors.forename: Antonio
authors.initials: A
authors.lastname: Garcia-Jimenez
authors.affiliation: University of Murcia, Faculty of Veterinary, Group of Molecular Interactions in Membranes, Department of Biochemistry and Molecular Biology-A, 30100 Murcia, Spain.
authors.forename: Jose Antonio
authors.initials: JA
authors.lastname: Teruel-Puche
authors.affiliation: University of Murcia, Faculty of Chemistry, Group of Synthetic Organic Chemistry, Department of Organic Chemistry, 30100 Murcia, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Berna
authors.affiliation: University of Murcia, Faculty of Veterinary, GENZ-Group of Research on Enzymology (www.um.es/genz), Department of Biochemistry and Molecular Biology-A, 30100 Murcia, Spain.
authors.forename: José Neptuno
authors.initials: JN
authors.lastname: Rodriguez-Lopez
authors.affiliation: University of Murcia, Faculty of Veterinary, GENZ-Group of Research on Enzymology (www.um.es/genz), Department of Biochemistry and Molecular Biology-A, 30100 Murcia, Spain.
authors.forename: Jose
authors.initials: J
authors.lastname: Tudela
authors.affiliation: University of Murcia, Faculty of Veterinary, Group of Chemistry of Carbohydrates, Industrial Polymers and Additives, Department of Organic Chemistry, 30100 Murcia, Spain.
authors.forename: Pedro Antonio
authors.initials: PA
authors.lastname: Garcia-Ruiz
authors.affiliation: University of Murcia, Faculty of Veterinary, GENZ-Group of Research on Enzymology (www.um.es/genz), Department of Biochemistry and Molecular Biology-A, 30100 Murcia, Spain. Electronic address: canovasf@um.es.
authors.forename: Francisco
authors.initials: F
authors.lastname: Garcia-Canovas
mesh_terms: D007536:Isomerism; D007700:Kinetics; D062105:Molecular Docking Simulation; D012118:Resorcinols / Q000378:metabolism*; D013379:Substrate Specificity; D013816:Thermodynamics; D014443:Tyrosine / Q000378:metabolism*
chemical_list: D012118:Resorcinols; D014443:Tyrosine
keywords: 2-Methylresorcinol; 4-Ethylresorcinol; 4-Methylresorcinol; Alternative substrate; Inhibitor; Kinetic; Resorcinol; Tyrosinase