FORMATION OF A STABLE QUINONE METHIDE DURING TYROSINASE-CATALYZED OXIDATION OF ALPHA-METHYL DOPA METHYL-ESTER AND ITS IMPLICATION IN MELANIN BIOSYNTHESIS

被引：32

作者：

SUGUMARAN, M

DALI, H

SEMENSI, V

机构：

[1] Department of Biology, University of Massachusetts, Boston, MA 02125, Harbor Campus

来源：

BIOORGANIC CHEMISTRY | 1990年 / 18卷 / 02期

基金：

美国国家卫生研究院;

关键词：

D O I：

10.1016/0045-2068(90)90036-5

中图分类号：

Q5 [生物化学]; Q7 [分子生物学];

学科分类号：

071010 ; 081704 ;

摘要：

Mushroom tyrosinase-catalyzed oxidation of α-methyl dopa methyl ester resulted in the formation of "iminochrome" similar to the well-known dopa-dopachrome conversion. At pH 5, the iminochrome formed was found to be stable and accumulated in the reaction mixture. However, when the reaction was carried out under near neutral and slightly alkaline conditions, the iminochrome formed readily tautomerized into a quinone methide isomer, which accumulated in the reaction mixture. The structure of the quinone methide formed was established by ultraviolet and visible spectroscopy and cochromatography with a synthetic sample. These results demonstrate the facile generation of quinone methide from imunochrome under physiological conditions and strongly support the possible occurrence of a similar reaction during melanogenesis. © 1990.

引用

页码：144 / 153

页数：10

共 32 条

[1] PROTEIN CROSS-LINKING BY PEROXIDASE - POSSIBLE MECHANISM FOR SCLEROTIZATION OF INSECT CUTICLE [J].