Inactivation of hemagglutinating capacity of type A influenza virus by trypsin treatment.

Abstract

SummaryThe effect of trypsin on hemagglutinating capacity of 6 type A strains of influenza virus of human origin has been determined under different experimental conditions. With both virus and enzyme in tris-Cl buffer and incubation at 37°C the hemagglutinating capacity of all strains was rapidly inactivated. Minimum concentration of enzyme and minimum time required for inactivation was not the same for all strains. However, with all strains, lowering the incubation temperature or adding sodium or calcium chloride to the trypsin-virus mixtures either reduced the rate of the reaction or completely inhibited it. These changes in test conditions did not in all instances affect all strains to the same extent. With 5 of the 6 strains the effect of added salt appeared to be more closely associated with the concentration than the type of ion present, whereas with the sixth strain the type of ion was a significant factor. The findings illustrate the importance of both the strain examined and the experimental con...