Evidence for glycosyltransferases in trout liver microsomes (Salmo gairdneri)

1. Trout (Salmo gairdneri) serum is rich in glycoproteins which are synthetized in liver. 2. An attempt to localize glycosyltransferases in hepatocytes is described, using cellular fractionation and marker enzyme determination. 3. Galactosyltransferase, mannosyltransferase, N-acetyl-glucosaminyl transferase, glucosyltransferase, sialyltransferase (on exogenous acceptor) are found in a microsomal fraction obtained by centrifugation at 117 X 10(5) g min of the post-mitochondrial supernatant. 4. Mannose is transferred to endogenous lipids and proteins.