title: Enzymological characteristics of avian influenza A virus neuraminidase.
abstract: Neuraminidases of 18 strains of avian influenza A virus were examined by both colorimetric and fluorometric assays using fetuin and 4-methylumbelliferyl-N-Ac-alpha-D-neuraminide as substrates, respectively, to compare them with those of human influenza A and B viruses. The ratios of the neuraminidase activity of avian influenza virus measured by the colorimetric assay method to that measured by the fluorometric assay were distributed in the range of 2.4-20.3. The enzyme of avian influenza virus showed calcium-ion dependence in both assay methods. These results suggest that neuraminidase of avian influenza A virus is varies greatly from one strain to another in substrate specificity as compared with those of human influenza A and B viruses, and that some strains of avian influenza A virus have a neuraminidase with unique enzymological characteristics different from that of human influenza A virus as well as that of influenza B virus.
mesh_terms: D003124:Colorimetry; D004492:Edetic Acid / Q000494:pharmacology; D000939:Epitopes; D005470:Fluorometry; D009980:Influenza A virus / Q000201:enzymology*; D009439:Neuraminidase / Q000378:metabolism*; D013045:Species Specificity; D013379:Substrate Specificity
chemical_list: D000939:Epitopes; D004492:Edetic Acid; D009439:Neuraminidase