N-Glycolylneuraminic acid (Neu5Gc) is an oncofetal antigen in humans and is developmentally regulated in rodents. We have explored the biology of N-acetylneuraminic acid hydroxylase, the enzyme responsible for conversion of the parent sialic acid, N-acetylneuraminic acid (Neu5Ac) to Neu5Gc. We show that the major sialic acid in all compartments of murine myeloma cell lines is Neu5Gc. Pulse-chas...

The role of sialic acid in the interaction of sialoglycoproteins with wheat germ agglutinin was investigated by using several well characterized saccharides and sialoglycoconjugates. N-Acetylneuraminic acid and neuramin 2 + 3 lactose, in addition to N-acetyl-Dglucosamine and its fil-+ 4 oligomers were found to be inhibitors of wheat germ agglutinin-induced hemagglutination. Neuraminic acid-/?-m...

The interaction between influenza virus hemagglutinin and its cell-surface receptor, 5-N-acetylneuraminic acid (sialic acid), was probed by the synthesis of 12 sialic acid analogs, including derivatives at the 2-carboxylate, 5-acetamido, 4-, 7-, and 9-hydroxyl, and glycosidic positions. The equilibrium dissociation constants of these analogs were determined by nuclear magnetic resonance spectro...

N-Acetylneuraminate lyases (NALs) or sialic acid aldolases catalyze the reversible aldol cleavage of N-acetylneuraminic acid (Neu5Ac, the most common form of sialic acid) to form pyruvate and N-acetyl-d-mannosamine. Although equilibrium favors sialic acid cleavage, these enzymes can be used for high-yield chemoenzymatic synthesis of structurally diverse sialic acids in the presence of excess py...

We examined the effect of experimental meningeal infection with a neuraminidase-producing strain of Diplococcus pneumoniae on the N-acetylneuraminic acid (NANA) content of canine cerebral cortical gray matter. The Warren thiobarbituric acid assay for NANA was used. There was no significant difference between the free and bound NANA levels of the tissue from control animals and from those with m...

Sialidases or neuraminidases catalyze the hydrolysis of terminal sialic acid residues from sialyl oligosaccharides and glycoconjugates. Despite successes in developing potent inhibitors specifically against influenza virus neuraminidases, the progress in designing and synthesizing selective inhibitors against bacterial and human sialidases has been slow. Guided by sialidase substrate specificit...

The molecular structure of a sulfated glycoprotein from chick chorioallantoic fluid has been investigated. The effect of alkali and alkali-borohydride under various conditions has been shown to lead to quantitatively and qualitatively different products of elimination and reduction. The carbohydrate chains of the products, by gel filtration, were heterogeneous, ranging from an average molecular...