AUC experiments - were performed on a Beckman Optima XL-I analytical ultracentrifuge. All samples were measured at 35 krpm and scanned at 281 nm and data were acquired in intensity mode. All samples were measured in a buffer containing 50 mM TRIS-HCl, pH 7.4; 150 mM NaCl, and 1 mM EDTA. Data were analyzed with UltraScan-III ver. 3.1, release 1964.
