Newcastle sialidase

Ajisaka et al. examined different sialidase somces and found that Newcastle disease virus (NDV) sialidase afforded predominantly the a-2,3 regioisomers, while Arthrobacter ureafaciens and Clostridium perfringens sialidases, in addition to the Vibrio cholerae sialidase examined by Thiem, favored the a-2,6-linked products [53]. Unfortunately, the reaction yields did not improve for the new enzymes, varying from 0.8% to 3.6% isolated yield. In the case of NDV sialidase, the high selectivity for a-2,3-sialosides stemmed from a large a-2,6/a-2,3 hydrolysis ratio. Hydrolysis of the a-2,6 products was found to be 28 times faster than the a-2,3 isomers. Inter-... 

L. Anastasia, J. Holguera, A. Bianchi, F. D Avila, N. Papini, C. Tringali, E. Monti, E. Villar, B. Venerando, I. Munoz-Barroso, and G. Tettamanti, Overexpression of mammalian sialidase NEU3 reduces Newcastle disease virus entry and propagation in COS7 cells, Biochim. Biophys. Acta, 1780 (2008) 504-512. 

The positional specificity of sialidases can be monitored by the action of the enzymes on mixtures of isomeric sialyllactoses (Friebolin et al. 1981c). In the same study also kinetic parameters of these enzyme reactions were determined. For sialidase isolated from Newcastle disease virus Paulson et al. (1982) demonstrated by 500 MHz H-NMR spectroscopy that this enzyme hydrolyzes preferentially sialic acid residues a(2-3)-linked to aj-acid glycoprotein. 

A number of pathogens also have sialidases to aid in pathogenesis or nutrition. Orthomyxoviruses (e.g. influenza) and paramyxoviruses (e.g. mumps, parainfluenza, Newcastle disease, Sendai) have sialidases on their surfaces. Surface sialidase activity is also exhibited by parasites such as Trypanosoma cruzi, T. brucei as well as a number of both pathogenic and non-pathogenic bacteria which may also secrete the enzyme. 

J.C. Paulson, J. Weinstein, L. Dorland, H. van Halbeek and J.F. Vliegenthart, Newcastle disease virus contains a linkage-specific glycoprotein sialidase. J. Biol Chem., 1982, 257, 12734— 12738. 

Garcia-Sastre, A., Cobaleda, C., Cabezas, J. A., and Villar, E., 1991, On the inhibition mechanism of the sialidase activity from Newcastle disease virus, Biol. Chem. Hoppe-Seyler 372 923-927. 

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