Delineation of fucosyltransferase activities with thiol reagents.
The thiol reagent dithiothreitol inhibits the activity of a core GDP-fucose-N-acetylglucosaminide alpha-6-fucosyltransferase in plasma and blood-cell homogenates, while promoting the activity of alpha-2- and alpha-3-fucosyltransferases. The latter enzymes catalyse transfer of fucose on to terminal galactose and subterminal N-acetylglucosamine residues respectively. A thiol-blocking reagent N-ethylmaleimide does not affect the activity of the alpha-6-fucosyltransferase, but inhibits the other two enzymes. These results indicate the presence of a critical disulphide linkage in the alpha-6-fucosyltransferase, and provide a means of delineation of different fucosyltransferases.
D055598:Chemical Phenomena; D002621:Chemistry; D004229:Dithiothreitol / Q000494:pharmacology*; D005033:Ethylmaleimide / Q000494:pharmacology*; D005647:Fucosyltransferases / Q000037:antagonists & inhibitors* / Q000097:blood; D006602:Hexosyltransferases / Q000037:antagonists & inhibitors*; D006801:Humans; D007938:Leukemia / Q000201:enzymology
D005647:Fucosyltransferases; D006602:Hexosyltransferases; D005033:Ethylmaleimide; D004229:Dithiothreitol