Figure 9.
FIM5 Binds Actin Filaments with High Affinity.
(A) Production of recombinant FIM5 protein. Lane 1, molecular mass standard; lane 2, purified FIM5 protein.
(B) A high-speed cosedimentation assay was used to assess FIM5 binding to actin filaments. Lanes 1 and 2 contain actin alone, lanes 3 and 4 contain actin and 2 μM FIM5, and lanes 5 and 6 contain 2 μM FIM5 alone. S, supernatant; P, pellet.
(C) The concentration of bound FIM5 or FIM1 was plotted against the concentration of free FIM5 or FIM1 and fitted with a hyperbolic function. The representative Kd values for this particular experiment were 0.75 and 0.51 μM for FIM5 and FIM1, respectively.