Comparison of MHCK-B and its truncations for co-sedimentation with myosin II bipolar filaments. (A) Kinase fusion proteins (0.1 μM) were incubated with myosin filaments (1.0 μM) as described previously . Reaction mixes were centrifuged and equal volumes of the resulting pellets (P) and supernatants (S) were subjected to SDS-PAGE and the kinase fusion proteins were identified by Western blotting with anti-GST antibody. (B) Bar graph of kinase constructs binding to myosin II. Co-sedimentation values were quantified by densitometric analysis of the Western blot, and the amount of fusion protein in the pellet fraction was divided by that in both the pellet and supernatant and multiplied by 100%. The bars represent the average values from at least three separate experiments and the vertical lines are the standard errors of those means.