Mechanistic aspects of the tyrosinase oxidation of hydroquinone.
Contradictory reports on the behaviour of hydroquinone as a tyrosinase substrate are reconciled in terms of the ability of the initially formed ortho-quinone to tautomerise to the thermodynamically more stable para-quinone isomer. Oxidation of phenols by native tyrosinase requires activation by in situ formation of a catechol formed via an enzyme generated ortho-quinone. In the special case of hydroquinone, catechol formation is precluded by rapid tautomerisation of the ortho-quinone precursor to catechol formation.
Lennard-Jones Laboratories, School of Physical and Geographical Sciences, Keele University, Staffordshire ST5 5BG, UK. Electronic address: c.a.ramsden@keele.ac.uk.
Christopher A
CA
Ramsden
Totteridge Institute for Advanced Studies, The Grange, Grange Avenue, London N20 8AB, UK.
Patrick A
PA
Riley
D002396:Catechols / Q000737:chemistry / Q000378:metabolism; D006873:Hydroquinones / Q000737:chemistry / Q000378:metabolism*; D015394:Molecular Structure; D014442:Monophenol Monooxygenase / Q000737:chemistry / Q000378:metabolism*; D010084:Oxidation-Reduction; D010636:Phenols / Q000737:chemistry / Q000378:metabolism; D013816:Thermodynamics
D002396:Catechols; D006873:Hydroquinones; D010636:Phenols; D014442:Monophenol Monooxygenase; C034221:catechol; C031927:hydroquinone
Hydroquinone; Tautomerism; Tyrosinase; ortho-Quinones; para-Quinones