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B6db references: 86295644

type Journal Article
authors Tomisawa, H.; Ichihara, S.; Fukazawa, H.; Ichimoto, N.; Tateishi, M.; Yamamoto, I.
title Purification and characterization of human hepatic cysteine-conjugate beta-lyase
journal Biochem J
ui 86295644
year (1986)
volume 235
number 2
pages 569-75.
keywords Chromatography, Gel
abstract Cysteine-conjugate beta-lyase (EC was purified about 880-fold from human liver obtained post mortem. The purification procedure included (NH4)2SO4 precipitation, chromatography on DEAE-cellulose and hydroxyapatite, gel filtration on Sephadex G-200, and chromatofocusing. The purified enzyme cleaves the C-S bond of several S-aryl-L-cysteines to yield equimolar amounts of thiols, pyruvic acid and ammonia via an alpha beta-elimination reaction. The Mr of the enzyme was estimated to be 88,000 by gel filtration. The enzyme is thermolabile, has a pH optimum of 8.5, and an apparent Km of 0.7 mM towards S-(p-bromophenyl)- L-cysteine. The enzyme requires pyridoxal 5'-phosphate as a cofactor, and hence the enzyme activity was completely abolished by hydroxylamine. No effect of EDTA or thiol-blocking reagents was observed on the activity of the enzyme.
last changed 2002/11/12 16:17

B6db references