Deglycosylation with trifluoromethanesulfonic acid differentially affects inhibitor activities of turkey ovomucoid.
Turkey ovomucoid is an inhibitor of both trypsin and chymotrypsin. Treatment of this glycoprotein with trifluoromethanesulfonic acid in anisole resulted in time-dependent removal of carbohydrate and altered its biological activity. After 6 h of treatment the apparent molecular mass obtained by SDS-PAGE decreased from 38 to 30 kDa. Carbohydrate analyses indicated loss of 94% of original saccharide residues. The inhibitory activity of each domain was analyzed independently by comparing enzymic activity of trypsin and chymotrypsin in the absence of inhibitor to that preincubated in the presence of varying amounts of native or deglycosylated ovomucoid, respectively. The results demonstrated that removal of saccharides with trifluoromethanesulfonic acid differentially affects the inhibitor activities of turkey ovomucoid. Decreased inhibitory activity of the trypsin domain was observed with casein and benzoyl arginine ethyl ester as substrates. In contrast, enhanced inhibitory activity of the chymotrypsin domain was observed with benzoyl tyrosine ethyl ester and methyl-O-succinyl-Arg-Pro-Tyr-p-nitroanilide, good substrates for chymotrypsin, but not with casein.
Department of Biochemistry, Wayne State University School of Medicine, Detroit, MI 48201.
D
D
Dabich
E C
EC
Yurewicz
V A
VA
Battel
D000818:Animals; D002241:Carbohydrates / Q000032:analysis; D002364:Caseins / Q000378:metabolism; D002918:Chymotrypsin / Q000037:antagonists & inhibitors; D006031:Glycosylation / Q000187:drug effects; D008698:Mesylates / Q000494:pharmacology*; D008956:Models, Chemical; D010059:Ovomucin / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D013379:Substrate Specificity; D014361:Trypsin Inhibitors / Q000494:pharmacology; D014422:Turkeys
D002241:Carbohydrates; D002364:Caseins; D008698:Mesylates; D014361:Trypsin Inhibitors; D010059:Ovomucin; D002918:Chymotrypsin; C012077:trifluoromethanesulfonic acid