Synthetic disialyl hexasaccharides protect neonatal rats from necrotizing enterocolitis.

Two novel synthetic α2-6-linked disialyl hexasaccharides, disialyllacto-N-neotetraose (DSLNnT) and α2-6-linked disialyllacto-N-tetraose (DS'LNT), were readily obtained by highly efficient one-pot multienzyme (OPME) reactions. The sequential OPME systems described herein allowed the use of an inexpensive disaccharide and simple monosaccharides to synthesize the desired complex oligosaccharides with high efficiency and selectivity. DSLNnT and DS'LNT were shown to protect neonatal rats from necrotizing enterocolitis (NEC) and are good therapeutic candidates for preclinical experiments and clinical application in treating NEC in preterm infants.

A sialyltransferase mutant with decreased donor hydrolysis and reduced sialidase activities for directly sialylating LewisX.

Glycosyltransferases are important catalysts for enzymatic and chemoenzymatic synthesis of complex carbohydrates and glycoconjugates. The glycosylation efficiencies of wild-type glycosyltransferases vary considerably when different acceptor substrates are used. Using a multifunctional Pasteurella multocida sialyltransferase 1 (PmST1) as an example, we show here that the sugar nucleotide donor hydrolysis activity of glycosyltransferases contributes significantly to the low yield of glycosylation when a poor acceptor substrate is used.

Highly efficient chemoenzymatic synthesis of β1-3-linked galactosides.

A novel D-galactosyl-β1-3-N-acetyl-D-hexosamine phosphorylase cloned from Bifidobacterium infantis (BiGalHexNAcP) was used with a recombinant E. coli K-12 galactokinase (GalK) for efficient one-pot two-enzyme synthesis of T-antigens, galacto-N-biose (Galβ1-3GalNAc), lacto-N-biose (Galβ1-3GlcNAc), and their derivatives.