Figure 1

Interaction between RSV P protein and profilin in vitro. Ni⁺²-agarose matrix with bound His-tagged P protein was incubated with either of the following, and the bound proteins analyzed as described under Materials and Methods: none (lane 1), 2 μg profilin (lane 2), 40 μg S100 extract of A549 cells (see Materials and Methods) (lane 4), A549 extract as in lane 4 except that it was pre-incubated with 10 μg of purified P protein at room temperature for 5 min (lane 5). About 90% of the eluted material was analyzed by SDS-PAGE and staining with Coomassie Blue R250 (left); the rest divided into equal parts and analyzed in parallel Western blots using anti-P or anti-profilin antibody (right). Lane 1 represents eluate from a blank Ni⁺²-column to which no P protein was bound. Molecular weights of protein size markers are indicated in the middle (62 through 16 kDa). The P and the profilin bands are so indicated.