Hansruedi Dr. Lötscher

Purification of the N-acetylglucosaminide alpha(1-3/4)fucosyltransferase of human milk.

TheN-acetylglucosaminide α(1–3/4)fucosyltransferase has been purified 1.8×106-fold from human milk by ion-exchange chromatography, affinity chromatography of GDP-agarose and HPLC. The α(1–3/4)fucosyltransferase behaves in gel filtration-HPLC as a molecule of Mr 98 000, and differs from the α(1–3)fucosyltransferase which behaves like a molecule of about Mr 47 000. The enzyme is a glycoprotein, and the purified preparation appears in SDS polyacrylamide gel electrophoresis as a band of Mr 44 000. The results present the first purification of human milk α(1–3/4)fucosyltransferase to apparent homogeneity, and suggest that the α(1–3/4)- and α(1–3)fucosyltransferases of human milk differ in their native molecular sizes, the former being a dimer of two subunits.