AN EMPIRICAL RELATIONSHIP BETWEEN ROTATIONAL CORRELATION TIME AND SOLVENT ACCESSIBLE SURFACE-AREA

Structure-dynamics interrelationships are important in understanding p rotein function. We have explored the empirical relationship between r otational correlation times (tau(c)) and the solvent accessible surfac e areas (SASA) of 75 proteins with known structures. The theoretical c orrelation between SASA and tau(c) through the equation SASA = K(r)tau (c)((2/3)) is also considered. SASA was determined from the structure, tau(c)(calc) was determined from diffusion tensor calculations, and t au(c)(expt) was determined from NMR backbone C-13 or N-15 relaxation r ate measurements. The theoretical and experimental values of tau(c) co rrelate with SASA with regression analyses values of K-r as 1696 and 1 896 m(2)s(-(2/3)), respectively, and with corresponding correlation co efficients of 0.92 and 0.70.