Study of a new strain of paramyxoviruses isolated from wild ducks: structural polypeptides.

By polyacrylamide gel electrophoresis, Duck/Mississippi/75 virus was shown to contain five different types of polypeptides of mol. wt. ranging from 76 X 1O(3) to 43 X 10(3), two of which were glycosylated (mol. wt. 76 X 10(3) and 57 X 10(3). A comparison of this data with similar results obtained using Yucaipa and Newcastle disease virus (NDV) revealed a similarity with NDV, concerning the number, position and mol. wt. of the polypeptides. Haemagglutinating and neuraminidase properties are associated with surface glycoproteins which represent at least 40% of the virus protein. After KCl and Triton X-100 treatment and centrifugation on linear sucrose density gradients (10 to 25%, w/w) it was possible to isolate glycoprotein VP1 of mol. wt 76 X 10(3) with which haemagglutinating and neuraminidase activities were associated.