Analysis of proteins present in virions of parental and F protein cleavage site mutant APMV-4 viruses, and cell-surface expression of the viral F protein.

<p>(A) Virus that was partially purified from infected chicken egg allantoic fluids by sucrose step gradients was separated by electrophoresis, and the gel was stained with Coomassie brilliant blue. Lanes: 1. Biologically-derived APMV-4, 2. rAPMV-4, 3. rAPMV-4/Fc type 3-Q, 4. rAPMV-4/Fc type 5-Q, 5. rAMPV-4/Fc BC, 6. rAMPV-4/Fc Las, 7. rAMPV-4/Fc SV, and 8. rAMPV-4/Fc PIV-1 (B) Incorporation of wild-type and mutated F proteins into the virions was further analyzed by Western blot. The separated proteins in the gel (8%) under reducing condition (in panel A) were transferred into a membrane, and the F protein was detected by using an antiserum raised against a synthetic peptide from the F protein of APMV-4. (C) Surface expression of the F protein on infected DF1 cells. DF1 cells were infected with each virus (MOI of 0.1) and, at 24 h post-infection, were stained with anti-peptide antiserum against the F protein followed by anti-Alexa Fluor 488 antibody, and were analyzed by flow cytometry.