A mouse lymphoma cell line resistant to the leukoagglutinating lectin from Phaseolus vulgaris is deficient in UDP-GlcNAc: alpha-D-mannoside beta 1,6 N-acetylglucosaminyltransferase.
A UDP-G1cNAc:a-mannoside p1,6 N-acetylglucosaminyltransferase was identified in cell-free preparations from the mouse lymphoma cell line BW5147.A novel assay employing concanavalin A-Sepharose, lentil lectin-Sepharose, and radioiodinated glycopeptide acceptors was devised to specifically measure the activity of this enzyme.The enzyme transfers N-acetylglucosamine to the C-6 position of a-linked mannose residues and utilizes as acceptors biantennary Asnlinked oligosaccharides containing N-acetylglucosamine, but not sialic acid or galactose, at the nonreducing termini.The product of the enzyme is a triantennary glycopeptide.The level of this enzyme activity was markedly decreased in a mouse lymphoma cell line (BW5147-PHAR2.1),which has previously been shown to be resistant to the cytotoxic effects of the leukoagglutinating lectin (L-PHA) from Phaseolus vulgaris (Trowbridge, I.