Evidence for Two CMP-N-acetylneuraminic Acid: Lactose Sialyltransferases in Rat, Porcine, Bovine, and Human Liver

Abstract

Evidence is presented for two sialyltransferases catalyzing formation of sialyl-(2 → 3)-lactose and sialyl-(2 → 6)-lactose in fetal and adult livers from rats, pigs, beef, and humans. In rat and porcine liver, the ratio of the rates of formation of these products varied with age. This ratio also varied with the pH of incubation for all four species. The implications of these findings in the control of glycoprotein biosynthesis are discussed.