Purification of human liver glycoprotein sialyltransferase by affinity chromatography

A simple procedure has been developed for purifying solubilized human liver glycoprotein sialyltransferase (EC 2.4.99.1) 16 000-fold in 4–5% yield. The procedure involves two centrifugation steps, affinity chromatography of the ultrasupernatant fluid on cytidine diphosphate-hexanolamine-agarose followed by gel filtration on Sephadex G-150. Sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) indicated that the purified sialyltransferase preparation contains approximately equivalent amounts of three protein bands (with apparent molecular weights of 61 000, 63 000 and 70 000) and is highly purified if not homogeneous.