Analysis of G, F and M proteins in HMPV-infected cells. At 10 days post-infection (dpi) mock-infected (M) and HMPV-infected (I) cells were extracted in boiling mix and analysed by immunoblotting with (A) anti-G or (B) anti-M. Protein species corresponding in size to G protein (G) and a larger G protein species (G*), and the matrix protein (M) are indicated. (C and D). At 10 dpi mock-infected (M) and HMPV-infected (I) cells were surface-biotinylated using sulpho-NHS-LC-LC-biotin as described previously ( ). The surface-labelled detergent extract was immunoprecipitated using (C) MAbAT1 (anti-G) or MAb58 (anti-F). The biotin-labelled proteins were immunoblotted and detected using strepavidin-HRP. Surface-biotinylated protein species corresponding in size to G, G*, and the F1 subunit (F1) are indicated. (D) Mock and HMPV-infected cells at 10 dpi were labelled for 16 hr using 100 μC/ml L-[35 S]-methionine (EasyTag, PerkinElmer) in methionine free-DMEM (Invitrogen) and the detergent extracts immunoprecipitated using MAb58 as described previously . The F0 and F1 subunit are indicated. In plate C and D additional protein products that are immunoprecipitated with anti-F are indicated (*).