Synthesis of hydroxymethylglutathione from glutathione and L-serine catalyzed by carboxypeptidase Y.
Hydroxymethylglutathione (gamma-L-glutamyl-L-cysteinyl-L-serine; hmGSH) occurs in many species belonging to the family Gramineae, but the biosynthetic pathway for hmGSH has not been identified. We found that carboxypeptidase Y (CPY), but not carboxypeptidase A, catalyzed hmGSH synthesis from glutathione and L-serine in vitro at acidic pH. CPY also catalyzed methylglutathione synthesis from glutathione and L-alanine. These findings suggested that a carboxypeptidase-like enzyme may be involved in hmGSH synthesis in vivo.
Okumura
Ryosuke
R
Division of Applied Life Sciences, Graduate School of Agriculture, Kyoto University, Kyoto 606-8502, Japan.
Koizumi
Yukio
Y
Sekiya
Jiro
J
D000409:Alanine / Q000378:metabolism; D002268:Carboxypeptidases / Q000378:metabolism*; D002384:Catalysis; D043402:Cathepsin A; D002851:Chromatography, High Pressure Liquid; D005978:Glutathione / Q000031:analogs & derivatives* / Q000096:biosynthesis* / Q000378:metabolism*; D006863:Hydrogen-Ion Concentration; D006900:Hydroxylation; D012694:Serine / Q000737:chemistry / Q000378:metabolism*; D015003:Yeasts / Q000201:enzymology
C029469:S-hydroxymethylglutathione; D012694:Serine; D002268:Carboxypeptidases; D043402:Cathepsin A; D005978:Glutathione; D000409:Alanine