Selective inhibition of glycosyltransferases by bivalent imidazolium salts.

Galactosyltransferases (GalTs) extend the glycan chains of mammalian glycoproteins by adding Gal to terminal GlcNAc residues, and thus build the scaffolds for biologically important glycan structures. We have shown that positively charged bivalent imidazolium salts in which the two imidazolium groups are linked by an aliphatic chain of 20 or 22 carbons form potent inhibitors of purified human β3-GalT5, using GlcNAcβ-benzyl as acceptor substrate. The inhibitors are not substrate analogs and also inhibited a selected number of other glycosyltransferases. These bis-imidazolium compounds represent a new class of glycosyltransferase inhibitors with potential as anti-cancer and anti-inflammatory drugs.