Protease susceptibility of human A influenza virus polypeptides.

ABSTRACT

The proteolytic susceptibility of polypeptides of four antigenically distinct subtypes of influenza a virus strains of human origin was studied. The extent of degradation of polypeptide molecules of strains A/PR/8/34 (H0N1) (PR), A/FM/1/47 (H1N1), A/Singapore/1/57 (H2N2) and A/Hong Kong/8/68 (H3N2), assessed by densitometry of gels after sodium dodecylsulfate polyacrylamide gel electrophoresis was variable by treatment with trypsin. Also, sequential treatment of PR strain initially with phospholipase D followed by proteases of different specificities suggested differences in susceptibility of surface and internal polypeptide molecules. The significance of these results is discussed.