Inhibitory effects of various sulfur compounds on the activity of bovine erythrocyte enzymes.
Studies were conducted to assess the in vitro effects of selected sulfur compounds on the activities of superoxide dismutase (SOD), catalase, glutathione peroxidase (GSHPX), and glucose-6-phosphate dehydrogenase (G6PDH) in hemolyzates of bovine erythrocytes. All sulfur compounds produced concentration-dependent inhibition in the activities of these enzymes, but their effects on each enzyme were different. SOD and catalase activities were most sensitive to sulfide (S2-), followed by sulfite (SO3(2-)) and sulfate (SO4(2-)). GSHPX activity was most sensitive to SO3(2-), followed by S2-, cysteine and SO4(2-). The activity of G6PDH, however, was maximally inhibited by reduced glutathione (GSH), followed by SO3(2-) and SO4(2-); S2- was inhibitory only at high concentrations. Dialysis of the S2- and SO3(2-)-inhibited enzymes resulted in complete or partial reversal of inhibitory effects. The biochemical significance of these effects in relation to erythrocyte physiology is discussed.
Animal Sciences Wing, Alberta Environmental Centre, Vegreville, Alberta, Canada.
A A
AA
Khan
M M
MM
Schuler
R W
RW
Coppock
D000818:Animals; D002374:Catalase / Q000037:antagonists & inhibitors / Q000097:blood*; D002417:Cattle; D003545:Cysteine / Q000494:pharmacology*; D004912:Erythrocytes / Q000201:enzymology*; D005954:Glucosephosphate Dehydrogenase / Q000037:antagonists & inhibitors / Q000097:blood*; D005979:Glutathione Peroxidase / Q000037:antagonists & inhibitors / Q000097:blood*; D007700:Kinetics; D013431:Sulfates / Q000494:pharmacology*; D013440:Sulfides / Q000494:pharmacology*; D013447:Sulfites / Q000494:pharmacology*; D013482:Superoxide Dismutase / Q000037:antagonists & inhibitors / Q000097:blood*
D013431:Sulfates; D013440:Sulfides; D013447:Sulfites; D005954:Glucosephosphate Dehydrogenase; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D003545:Cysteine