FIG 1.

RhCMV encodes an IgG binding protein. To detect IgG binding proteins, lysates from metabolically labeled TRFs were incubated with serum from RhCMV-naive RMs, and the total IgG was immunoprecipitated using protein A/G-agarose. Endoglycosidase H (EndoH) was added where indicated. (A) Uninfected cell lysate. (B) TRFs were infected with RhCMV 68-1 (MOI = 3) for 72 h prior to metabolic labeling. Infected cell lysates were either untreated or incubated with purified Fab fragments or whole serum. Immunoprecipitates were separated by SDS-PAGE, and protein bands were visualized by autoradiography. (C) TRFs were infected with RhCMV 68-1 or the low-passage-number isolate UCD59 (MOI = 3) for 72 h prior to metabolic labeling and immunoprecipitation. (D) TRFs were infected with RhCMV 68-1 or the indicated RhCMV and CyCMV low-passage-number isolates (MOI = 3) for 72 h prior to metabolic labeling. IgG immunoprecipitations after incubation with CMV-naive RM serum were performed using protein A/G-agarose. Arrows indicate a single EndoH-sensitive glycoprotein species. *, Nonspecific protein.