a novel gene defining a novel human udp - glcnac : galβ1 - 3galnaca β1 , 6glcnac - transferase , termed c2gnt3 , with unique enzymatic properties is disclosed . the enzymatic activity of c2gnt3 is shown to be distinct from that of previously identified enzymes of this gene family . the invention discloses isolated dna molecules and dna constructs encoding c2gnt3 and derivatives thereof by way of amino acid deletion , substitution or insertion exhibiting c2gnt3 activity , as well as cloning and expression vectors including such dna , cells transfected with the vectors , and recombinant methods for providing c2gnt3 . the enzyme c2gnt3 and c2gnt3 - active derivatives thereof are disclosed , in particular soluble derivatives comprising the catalytically active domain of c2gnt3 . further , the invention discloses methods of obtaining 1 , 6 - n - acetylglucosaminyl glycosylated saccharides , glycopeptides or glycoproteins by use of an enzymically active c2gnt3 protein or fusion protein thereof or by using cells stably transfected with a vector including dna encoding an enzymatically active c2gnt3 protein as an expression system for recombinant production of such glycopeptides or glycoproteins . methods are disclosed for the identification of agents with the ability to inhibit or stimulate the biological activity of c2gnt3 . furthermore , methods of using c2gnt3 in the structure - based design of inhibitors or stimulators thereof are also disclosed in the invention . also a method for the identification of dna sequence variations in the c2gnt3 gene by isolating dna from a patient , amplifying c2gnt3 - coding exons by pcr , and detecting the presence of dna sequence variation , are disclosed .