title: Trypanosoma vivax, stock V953: inhibitory effect of type A influenza virus anti-HAV8 serum on in vitro neuraminidase (sialidase) activity.
abstract: Trypanosoma vivax stock V953 lysates were observed to produce neuraminidase (sialidase EC 3.2.1.18) in vitro, which cleaved neuraminic (sialic) acid from the substrate fetuin. The neuraminidase activity was proportional to the number of trypanosomes in the lysates, with 0.44, 0.88, and 1.75 X 10(6) trypanosomes producing 1.4 +/- 0.06, 3.1 +/- 0.1, and 6.7 +/- 0.1 micrograms of sialic acid liberated, respectively. Equal numbers of unlysed and lysed trypanosomes produced approximately the same amount of the enzyme. Trypanosome eluates stored at room temperature appeared to have lost neuraminidase activities within 4 days. An inhibition test for identifying the neuraminidase antigen on influenza viruses was performed in vitro on the T. vivax lysates. The inhibition test, using Type A influenza virus anti-HAV8 serum, showed a highly significant (P less than 0.0001) reduction in neuraminidase activities. The effect of equal amounts of influenza antiserum on serially diluted trypanosome lysates showed that 1 ml of influenza anti-HAV8 serum would inhibit a mean of 6.74 +/- 0.18 micrograms of T. vivax stock V953 neuraminidase activity.
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000276:immunology*; D007106:Immune Sera; D009980:Influenza A virus / Q000276:immunology*; D009439:Neuraminidase / Q000037:antagonists & inhibitors* / Q000276:immunology; D013696:Temperature; D014345:Trypanosoma / Q000201:enzymology*
chemical_list: D000914:Antibodies, Viral; D007106:Immune Sera; D009439:Neuraminidase