CRP1 does not influence the bundling activity of α-actinin. α-Actinin and CRP1 were preincubated for 15 min at room temperature. Actin filaments were then added, incubated for 30 min at room temperature, and centrifuged at 10,000 × g. Proteins from the supernatant (S) and the pellet (P) were separated by electrophoresis and detected by Gelcode Blue staining (A). The percentage of total actin (B) and α-actinin and CRP1 (C) in the pellet was quantified as described in Experimental Procedures. n = 4 ± SEM.