Effects of some S-blocked glutathione derivatives on the prevalent glyoxalase II (a form) of rat liver.
The prevalent glyoxalase II (S-2-hydroxyacylglutathione hydrolase, EC 3.1.2.6, a form) of rat liver cytosol has been studied with a series of seven S-blocked glutathione derivatives. At pH 7.4 and 20 degrees C, only p-nitrobenzyl-S-glutathione was found completely inactive. All the other derivatives are linear competitive inhibitors of the enzyme. Ki values using S-D-lactoylglutathione as substrate are reported. Alkyl-S-glutathiones are weak inhibitors and their inhibition increases with the decrease of the length of the alkyl chain. The best inhibitors are those glutathione derivatives which contain a thioester bond (carbobenzoxy- and p-nitrocarbobenzoxy-S-glutathione) or a carbonyl group (p-chlorophenacyl-S-glutathione). Inhibition by carbobenzoxy-S-glutathione seems to be more complex since the double reciprocal plot shows deviation from linearity at low substrate concentration.
Principato
G B
GB
Department of Experimental Medicine, University of Perugia, Italy.
Talesa
V
V
Norton
S J
SJ
Giovannini
E
E
Rosi
G
G
D000818:Animals; D003600:Cytosol / Q000201:enzymology; D005978:Glutathione / Q000031:analogs & derivatives* / Q000494:pharmacology*; D007527:Isoenzymes / Q000037:antagonists & inhibitors*; D007700:Kinetics; D008099:Liver / Q000201:enzymology*; D051381:Rats; D013329:Structure-Activity Relationship; D013869:Thiolester Hydrolases / Q000037:antagonists & inhibitors*; D000099301:Hydroxyacylglutathione Hydrolase
D005978:Glutathione; D007527:Isoenzymes; D013869:Thiolester Hydrolases; D000099301:Hydroxyacylglutathione Hydrolase