Sialidase biological roles

Exact analysis of sialic acid is required in biologieal experiments where the biological role of sialic acid is frequently studied with the aid of sialidases, and the amount of sialic acids released is determined. This is also important for periodate oxidation studies on biological systems, where modification of sialic acids by periodate is only assumed, but chemical analysis of this effect by isolation and analysis of the modified sialic acids is seldom performed. These uncertainties in determinations of sialic acid can be overcome by the purification procedures already described. Furthermore, it must be stressed that unequivocal determination of the structure of a sialic acid, especially... 

Rosenberg, A., and Schengrund, C.-L., 1976b, Sialidases, in Biological Roles of Sialic Acid (A. Rosenberg and C.-L. Schengrund, eds.). Plenum Press, New York, pp. 295-359. 

Several workers have tried to ascertain the effects of mammalian sialidase action on endogenous substrates. Studies of the effects of soluble microbial sialidases on cell-surface properties and on the activities of sialocompounds have been performed in order to try to determine, by analogy, the role of mammalian sialidase. This part of the chapter will summarize what is known about mammalian, and where possible, avian sialidase and will suggest biological roles for the enzyme. 

Once chemoenzymatically produced, these unnatural sialosides have demonstrated utility in a variety of biological applications. A sialoside consisting of 9-0-acetylated sialyl Tn antigen (sTn) was produced by one-pot synthesis and conjugated to human serum albumin to be used to evaluate the role of acetylation in carbohydrate-protein interactions. Para-nitrophenol-tagged sialosides can be used in a colorimetric assay to evaluate sialidase specificity. Biotin-tagged sialosides have been immobilized on a streptavidin-coated surface to study protein-carbohydrate interactions with surface plasmon resonance techniques. Size-defined... 

Although in silica analysis of large-scale gene expression data offers some interesting clues about the biological relevance of sialidases in different tissues and cell types, there remains of course the need of more specific and deeper studies, both at the RNA and at the protein level, to better define the role of these enzymes in health and disease. 

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