FIG. 4.

Immunoprecipitation analysis of GP₃ expressed by SFV-ORF3 or by LV. (A) GP₃ was immunoprecipitated with anti-GP₃ (α-GP₃) from lysates of BHK-21 cells infected with SFV-ORF3 at an MOI of 5. At 18 h p.i., the cells were starved for methionine for 30 min and subsequently labeled with l-[³⁵S]methionine for 30 min. The cells were then chased with 5 mM nonradioactive l-methionine for 0, 150, and 300 min. (B) GP₃ was immunoprecipitated with α-GP₃ from lysates of MARC-145 cells infected with LV4.2.1. Cells were infected with LV4.2.1 at an MOI of 2, and at 18 h p.i., they were labeled with l-[³⁵S]methionine for 30 min and chased for 300 min. (C) GP₃ was immunoprecipitated with α-GP₃ from extracellular LV4.2.1 virions labeled and purified by sedimentation through a sucrose cushion as described previously (25). Immunoprecipitates were treated with EndoH (H) or PNGaseF (F) or were left untreated (U).