Figure 5. SEC-measuredK_Dfor p53(1–93) at room temperature.

Panel A shows a comparison of K_D to molecular weight for wild type, ALA⁻, PRO⁻, and ALA⁻PRO⁻ (filled circles). Open circles are K_D measured for chicken albumin (44.3 kDa), bovine erythrocyte carbonic anhydrase (29.8 kDa, indicated as CA in the figure), staphylococcal nuclease (16.9 kDa), and horse myoglobin (16.95 kDa). Reported K_D were the average of at least 3 measurements for each protein with error bars representing the standard deviations. Panel B shows a comparison of K_D to R_h. Open circles are R_h estimated as one-half the maximum C_α-C_α distance in the crystallographic structures of albumin (48), carbonic anhydrase (49), nuclease (50), and myoglobin (51). The dashed line is a linear fit of R_h to K_D applied to the open circles. Filled circles show R_h measured by DLS at 25°C for wild type, ALA⁻, PRO⁻, ALA⁻PRO⁻, carbonic anhydrase, and nuclease. K_D were measured using 0.2 mg/mL samples of protein in 10 mM sodium phosphate, 100 mM sodium chloride, pH 7. DLS measurements used identical solution conditions except for 0.25–0.75 mg/mL protein concentrations.