A novel pathway for formation of thiol metabolites and cysteine conjugates from cysteine conjugate sulphoxides.
p-Bromothiophenol and S-(p-bromophenyl)-L-cysteine were formed enzymatically from S-(p-bromophenyl)-L-cysteine sulphoxide in the in vitro systems with isolated rat hepatocytes or purified cysteine conjugate beta-lyases. Isotope dilution study with non-radiolabelled carrier of each product suggested the initial liberation of the thiol and subsequent formation of the cysteine conjugate. C-S bond cleavage pathway to liberate sulphenic acid and thiol are postulated to play an important role in in vivo generation of toxic intermediates and products from cysteine conjugates.
Tomisawa
H
H
Upjohn Pharmaceuticals Limited Tsukuba Research Laboratories, Ibaraki, Japan.
Hayashi
M
M
Fukushima
M
M
Iida
S
S
Uda
F
F
Hattori
K
K
Tateishi
M
M
D000818:Animals; D013437:Carbon-Sulfur Lyases; D002478:Cells, Cultured; D003545:Cysteine / Q000031:analogs & derivatives* / Q000378:metabolism / Q000494:pharmacology; D008099:Liver / Q000378:metabolism; D008190:Lyases / Q000378:metabolism*; D051381:Rats; D013434:Sulfenic Acids / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000378:metabolism*; D013454:Sulfoxides / Q000378:metabolism* / Q000494:pharmacology
D013434:Sulfenic Acids; D013438:Sulfhydryl Compounds; D013454:Sulfoxides; C071152:S-(bromophenyl)cysteine; C083788:S-(4-bromophenyl)cysteine sulfoxide; D008190:Lyases; D013437:Carbon-Sulfur Lyases; C019969:S-alkylcysteine lyase; D003545:Cysteine