DETERMINATION OF N-ACETYLGLUCOSAMINYLTRANSFERASE-III, N-ACETYLGLUCOSAMINYLTRANSFERASE-IV AND N-ACETYLGLUCOSAMINYLTRANSFERASE-V IN NORMAL AND HEPATOMA TISSUES OF RATS

N-Acetylglucosaminyltransferase III, IV and V activities were assayed in various rat tissues and hepatomas using the same fluorescence-labeled sugar chain, GlcNAcβ1-2Manα1-3(GlcNAcβ1-2Manα1-6)Manβ1-4GlcNAcβ1-4GlcNAc-2-aminopyridine as a substrate. The N-acetylglucosaminyltransferase II activity toward the substrate is the highest in most rat tissues including primary rat hepatoma. A relatively higher activity for GnT-V is found in small intestine, serum and hepatoma as compared to that of GnT-IV. Some kinetic properties of these enzymes in crude extracts were also determined. © 1990.