Figure 1.
Free p21 is a monomer. The buoyant molecular mass of recombinant p21 was determined by sedimentation equilibrium analytical ultracentrifugation and is 18,490 ± 772 daltons. A scan after 30 hr is shown. (Bottom) The raw concentration data determined using interference optics and the solid line drawn through the data points was obtained by fitting the fringe displacement vs. radial position to a single species model of equation 1 (see Materials and Methods). (Top) The residual difference between the experimental data and the fitted data for each point shown.