CHARACTERIZATION OF RAT N-ACETYLGLUCOSAMINYLTRANSFERASE-I EXPRESSED IN ESCHERICHIA-COLI

The catalytic domain (sGnT-I) of rat liver N-acetylglucosaminyltransfe rase I (GnT-I) was expressed in Escherichia coli. Lysates from pETsGnT -I transformants contained a prominent protein species of 46 kDa with which a significant GnT-I activity was associated, To purify the relev ant enzyme, we constructed cDNAs encoding sGnT-ICH and sGnT-INH, which had six additional histidine residues as an affinity tag at the C-ter minal and the N-terminal of sGnT-I, respectively, and introduced them into E. coli tells for expression. sGnT-INH was purified and its enzym atic properties were examined.