A cytosolic sialic acid-specific O-acetyl-esterase was previously described that can remove O-acetyl esters from the 9-position of sialic acids. We show that rat liver Golgi vesicles contain a distinct sialic acid-esterase located within the lumen of the same vesicles that add O-acetyl esters to sialic acids. Studies of a retinoblastoma cell line genetically deficient in the cytosolic enzyme al...

Although the vital roles of structures containing sialic acid in biomolecular recognition are well documented, limited information is available on how sialic acid structural modifications, sialyl linkages, and the underlying glycan structures affect the binding or the activity of sialic acid-recognizing proteins and related downstream biological processes. A novel combinatorial chemoenzymatic m...

In differential diagnosis of pleural effusions, cytology is the most sensitive method. Since cytology findings are positive in half of such fluids, combined use of reliable tumor marker and cytology is a logical approach. Sialic acid and other tumor markers can be reliable substances associated with neoplasia. The present study measured sialic acid levels in pleural effusion and serum samples o...

A low sialic acid content in low density lipoprotein (LDL) has been associated with atherogenicity and coronary artery disease (CAD) in many but not all studies. We investigated associations of the sialic acid-to-apolipoprotein B (apoB) ratio of LDL with lipoprotein lipid concentrations, kinetics of LDL, metabolism of cholesterol, and the presence of CAD in 98 subjects (CAD(+), n = 56; CAD(-), ...

Sialic acids are a diverse family of monosaccharides widely expressed on all cell surfaces of vertebrates and so-called "higher" invertebrates, and on certain bacteria that interact with vertebrates. This overview surveys examples of biological roles of sialic acids in immunity, with emphasis on an evolutionary perspective. Given the breadth of the subject, the treatment of individual topics is...

Introduction The sialic acids comprise a diverse family of nine-carbon keto-sugars, the majority of which are structural derivatives of neuraminic acid (Fig. 1). Neuraminic acid has an amino moiety at the C-5 position, and carboxylate at C-2 which confers negative charge at physiological pH. Whereas unsubstituted neuraminic acid is not known to exist in nature, over 40 substituted variations (c...

Sialic acid-binding immunoglobulin-like lectin-15 (Siglec-15) has been identified as a novel potential target for cancer immunotherapy. Here, we explored the role of Siglec-15 in human hepatoma cells. In this study, found that expression is substantially upregulated liver tissues comparison with nontumor tissues. Functionally, vitro experiments show promotes migration Furthermore, data demonstr...

Viruses of the Adenoviridae family are widespread in society and are associated with a wide variety of clinical symptoms in humans, including respiratory, gastrointestinal, and ocular diseases. Epidemic keratoconjunctivitis (EKC) is a severe ocular infection and is caused by the highly contagious adenoviruses Ad8, Ad19, and Ad37. Besides keratitis and conjunctivitis, other common symptoms of EK...

Metabolic incorporation of azide- or alkyne-modified sialic acids into the cellular glycosylation pathway enables the study of sialoglycan expression, localization, and trafficking via bioorthogonal chemistry. Herein, we report that such modifications of the sialic acid sugar can have a profound influence on their hydrolysis by neuraminidases (sialidase). Azidoacetyl (Az)-modified sialic acids ...

Sialic acid and glucuronic acid are monocarboxylated monosaccharides, which are normally present in sugar side chains of glycoproteins, glycolipids, and glycosaminoglycans. After degradation of these compounds in lysosomes, the free monosaccharides are released from the lysosome by a specific membrane transport system. This transport system is deficient in the human hereditary lysosomal sialic ...