CALIBRATION OF SIZE-EXCLUSION CHROMATOGRAPHY - USE OF A DOUBLE GAUSSIAN DISTRIBUTION FUNCTION TO DESCRIBE PORE SIZES

A method for the calibration of size-exclusion chromatographic columns is proposed that takes into account the nonlinear dependence of the Stokes radius R(8) upon the partition coefficient K-D. The method is based on the assumption that the pore size distribution of a molecular sieve column can be described by the sum of two Gaussian distributions and has been successfully tested with low-pressure chromatography gels (Sephacryl and Superose) and HPLC gels (TSK SW) over a wide range of protein sizes. An application of this method is described, in which aggregation states of the membrane protein prostaglandin H-2 synthase solubilized in nonionic detergents are estimated. (C) 1995 Academic Press, Inc.