RACK1 sedimentation velocity experiments. (A) Sedimentation velocity experiments were carried out at 4°C, 40,000 rpm (AN-60Ti rotor), and with scan data acquisition at 272 nm. Data were fitted using SedFit software (Version 11.8). Figure displays the c(S) fitting for RACK1 at concentrations of 0.1, 0.2 and 0.3 mg/mL. The c(S) curves suggest that RACK1 present a predominant specie and three or four others species with higher sedimentation coefficients (inset) (B) Plots of s20,ω (of the predominant specie) versus protein concentration fitted by linear regression to calculate the s0 20;w: 3.00 ± 0.01 Svedberg.