NEW ASSAYS FOR THE TYROSINE-HYDROXYLASE AND DOPA OXIDASE ACTIVITIES OF TYROSINASE

被引：262

作者：

WINDER, AJ

HARRIS, H

机构：

[1] Sir William Dunn School of Pathology, University of Oxford

来源：

EUROPEAN JOURNAL OF BIOCHEMISTRY | 1991年 / 198卷 / 02期

关键词：

D O I：

10.1111/j.1432-1033.1991.tb16018.x

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：

New assays for the tyrosine hydroxylase and dopa oxidase activities of tyrosinase (EC 1.14.18.1) have been developed. The tyrosine hydroxylase assay uses L-[carboxy-C-14]tyrosine as the substrate. (CO2)-C-14 is released from the products of the hydroxylation and further metabolism of L-[carboxy-C-14]tyrosine by incubation with ferricyanide, and measured radiometrically. D-Dopa is a preferable cofactor to L-dopa for the assay. Dopa oxidase activity is measured spectrophotometrically. Dopaquinone, produced on the oxidation of L-dopa, reacts with Besthorn's hydrazone (3-methyl-2-benzothiazolinone hydrazone) to form a pink pigment with an absorbance maximum at 505 nm. Details of the optimisation of conditions for the assays and their specificities for the two enzyme activities are described.

引用

页码：317 / 326

页数：10

共 38 条

[1]

BRADFORD MM, 1976, ANAL BIOCHEM, V72, P248, DOI 10.1016/0003-2697(76)90527-3

[2] A KINETIC-STUDY OF THE MELANIZATION PATHWAY BETWEEN L-TYROSINE AND DOPACHROME [J].