Sialidases molecular weights

GalNAc-protein (sialidase-treated ovine submaxillary mucin) InefiFective with low molecular weight acceptors NAN- (2 6) -GalNAc-protein Submaxillary glands (pork, sheep, bovine) fibroblasts Section V, A... 

The bacterial sialidases generally fall in the molecular weight range of 50,000 to 100,000 daltons. No definitive evidence for subunit structure is available. Multiple... 

Table 4. The influence of inhibitors on viral, bacterial and mammalian sialidases The strength of inhibition is indicated as weak (+) to very strong (-h + -H) or no inhibition (—). High (H) and low (L) molecular weight inhibitors are indicated and inhibition as competitive (C) or non-competitive (NC). ND, not determined... 

The crystal structures of two representative small sialidases, with molecular weights around 40 kDa, have been determined one from Salmonella typhimurium [17] and one from Micromonospora viridifaciens [I8j. These reveal the same P-propeller fold seen in the influenza virus neuraminidase (Figure 2), despite having no sequence similarity to the viral enzyme, and not containing any disulphide bonds in contrast to the seven conserved disulfides in the viral enzyme. 

Table I lists nonhormonal plasma sialoglycoproteins, and when known, their molecular weight, number of sialic acid residues per mole, and carbohydrate content. Sialic acid content was estimated by either the Warren procedure (1959) or by treatment with microbial sialidase and measurement of sialic acid release and concomitant change in electrophoretic mobility or isoelectric point. Some of the physical and biological changes observed in the plasma sialoglycoproteins after removal of sialic acid residues are described below.

Estimates of molecular weight based upon behavior of purified preparations of Diplococcus pneumoniae sialidase during molecular... 

While many roles have been proposed quite early for viral sialidase (viral penetration into the host cell, provision of lower-molecular-weight metabolites for viral propagation, release of newly formed virus from the host cell, destruction of substances which protect the cell surface from virus binding, viral binding to the host cell surface by enzyme-substrate interaction), conflicting lines of evidence for each hypothesis have prevented the certain adoption of any of them. For details in an old and a new review, see those by Kelly (1963) and Drzeniek (1972). More recently Tsvetkova and Lipkind (1973) have suggested that the viral... 

Over the past ten years there have been many papers published about mammalian sialidase and a few about avian sialidase. Organellar and subcellular distribution studies have been reported upon, as have substrate specificity, purification, physical properties and possible effects of enzyme action. Much of the work is suggestive but not complete, i.e., characterization of the physical properties such as the kinetic parameters, and Vmaxj has only been done on crude enzyme preparations. Composition, molecular weight, and mechanism of action are not known. 

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