Nature of Tyrosinase Inactivation in Melanosomes
نویسندگان
چکیده
منابع مشابه
CATECHOLASE (TYROSINASE) :* REVERSIBLE INACTIVATION AND REACTIVATIONt
Studies of the chemical properties of the enzyme, catecholase, have shown that this polyphenoloxidase consists of a copper-protein complex (l-3). Indications have also been obtained that the enzymic activity of catecholase is associated with the copper part of the molecule, since it has been found that the addition of certain reagents known to react with cupric ions will inhibit the enzymic act...
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The mechanisms that lead to variation in human skin and hair color are not fully understood. To better understand the molecular control of skin and hair color variation, we modulated the expression of Tyrosinase (Tyr), which controls the rate-limiting step of melanogenesis, by expressing a single-copy, tetracycline-inducible shRNA against Tyr in mice. Moderate depletion of TYR was sufficient to...
متن کاملIndirect inactivation of tyrosinase in its action on tyrosine.
Under aerobic conditions, tyrosinase is inactivated by dopa as a result of suicide inactivation, and, under anaerobic conditions, as a result of irreversible inactivation. However, tyrosine protects the enzyme from being inactivated by dopa under anaerobic conditions. This paper describes how under aerobic conditions the enzyme acting on tyrosine is not directly inactivated but undergoes a proc...
متن کاملPhenolic substrates and suicide inactivation of tyrosinase: kinetics and mechanism.
The suicide inactivation mechanism of tyrosinase acting on its substrates has been studied. The kinetic analysis of the proposed mechanism during the transition phase provides explicit analytical expressions for the concentrations of o-quinone against time. The electronic, steric and hydrophobic effects of the substrates influence the enzymatic reaction, increasing the catalytic speed by three ...
متن کاملThe mechanism of suicide-inactivation of tyrosinase: a substrate structure investigation.
Tyrosinase is a copper-containing mono-oxygenase, widely distributed in nature, able to catalyze the oxidation of both phenols and catechols to the corresponding ortho-quinones. Tyrosinase is characterised by a hitherto unexplained irreversible inactivation which occurs during the oxidation of catechols. Although the corresponding catechols are formed during tyrosinase oxidation of monophenols,...
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ژورنال
عنوان ژورنال: The Tohoku Journal of Experimental Medicine
سال: 1978
ISSN: 0040-8727,1349-3329
DOI: 10.1620/tjem.125.233