Synthesis of the carbocyclic analog of uridine 5'-(α-D-galactopyranosyl diphosphate) (UDP-gal) as an inhibitor of β(1 → 4)-galactosyltransferase

Abstract

Uridine 5'(5a-carba-α-D-galactopyranosyl diphosphate), the carbocyclic analog of UDP-galactose where the ring oxygen of the galactose residue is replaced by a methylene group, was chemically synthesized as a potential inhibitor of galactosyltransferase. It was found to be a competitive inhibitor of UDP-galactose: N-acetylglucosamine β(1 → 4)-galactosyltransferase from bovine milk (EC 2.4.1.22) with a K(i) value of 58 μM, similar to the K(m) value for UDP-galactose (25 μM).