Abstract
Sialyl and galactosyl transferase activities are demonstrated in calf vitreous hyalocytes. For study of sialyl transferase activity, a partially purified vitreous preparation (collagen and hyaluronic acid removed), and bovine submaxillary mucin were treated with an insolubilized neuraminidase before use as acceptor of radio-activity from CMP-[3H]-N-acetylneuraminic acid (CMP-[3H]-NAN). For study of galactosyl transferase activity the vitreous preparation was treated first with insolubilized neuraminidase and then with an insolubilized β-galactosidase before use as acceptor of radioactivity from UDP-[3H]-galactose (UDP-[3H]-gal). Galactosyl transferase requires a divalent metal ion for optimal activity, and the reactions catalyzed by each enzyme are dependent upon pH, time of incubation and concentration of enzyme and/or acceptor.