Weight average sedimentation coefficient, corrected to 20°C in water, versus concentration of Hsp27 (closed circles) or AC-Hsp27 (open squares). Buffer = 120 mM NaCl, 25 mM Tris, 2 mM MgCl2, 0.2 mM EGTA, 0.01% NaN3, 50 M PMSF, 5 mM DTT, and pH 7.5. The standard deviation of the data points is propagated from the noise in the original data set as described [37].