FIG. 5.

Dose-dependent F-actin binding determined by cosedimentation. Actin at concentrations of 0, 1.25, 2.25, 5, 10, and 20 μM was subjected to polymerizing conditions and incubated with 2.5 μM purified wild-type NCp7 (A), villin headpiece (B), or mutant NCp7 (C) before ultracentrifugation. The supernatants (S) and pellets (P) were separated after ultracentrifugation and analyzed by 15% tricine SDS-PAGE; the proteins were visualized by Coomassie blue staining.