Proteins specified by herpes simplex virus. IX. Contiguity of host and viral proteins in the plasma membrane of infected cells.

Artificial mixtures of plasma membrane vesicles produced by microcavitation from infected and uninfected cells band at the same density on isopycnic centrifugation in sucrose density gradient. However, after reaction with antiviral antibody, the density of the infected cell plasma membrane vesicles increases, and the infected and uninfected cell membranes are quantitatively separable on isopycnic centrifugation. Plasma membrane vesicles prepared from cells doubly labeled before and after infection with radioactive amino acids and reacted with antibody banded at a high density. Polyacrylamide gel electropherograms show that the vesicles reacted with antibody consist of both host- and virus-specific membrane proteins. Microcavitation does not disrupt viral envelopes since infectivity is not affected by this procedure. We conclude that viral and cellular proteins in the plasma membrane preparations are contiguous.