Mechanistic studies of the inactivation of tyrosinase by resorcinol.
The inactivation of tyrosinase by resorcinol (1,3-dihydroxybenzene) and seventeen simple derivatives has been investigated using combined spectrophotometry and oximetry together with hplc/ms examination of the oxidation products. The results are consistent with a Quintox mechanism, analogous to that proposed for catechol inactivation of tyrosinase, in which the resorcinol substrate is oxidised via the monooxygenase route leading to a hydroxy intermediate that undergoes deprotonation and results in irreversible elimination of Cu(0) from the active site. Hplc/ms evidence for formation of the resorcinol monooxygenase product (3-hydroxy-ortho-quinone) is presented and the relationship between the ring position of simple resorcinol substituents (H, Me, F, Cl) and tyrosinase inactivation is rationalised.
Gray Institute for Radiation Oncology and Biology, Department of Oncology, University of Oxford, Oxford OX3 7DQ, UK.
Michael R L
MR
Stratford
Christopher A
CA
Ramsden
Patrick A
PA
Riley
D020134:Catalytic Domain; D002396:Catechols / Q000737:chemistry / Q000378:metabolism; D003300:Copper / Q000737:chemistry / Q000378:metabolism; D007700:Kinetics; D014442:Monophenol Monooxygenase / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010084:Oxidation-Reduction; D010092:Oximetry; D011485:Protein Binding; D012118:Resorcinols / Q000737:chemistry / Q000378:metabolism*; D013053:Spectrophotometry
D002396:Catechols; D012118:Resorcinols; D003300:Copper; D014442:Monophenol Monooxygenase; C034221:catechol; C031389:resorcinol