DECONVOLUTION OF GEL-FILTRATION CHROMATOGRAPHS OF HUMAN PLASMA-LIPOPROTEINS

Gel filtration chromatographs of lipoproteins represent a superpositio n, or convolution, of the intrinsic polydispersity of the solute and t he dispersion due to transport phenomena. We describe a deconvolution technique for improving the resolution of gel filtration chromatograph s applicable to lipoproteins and other polydisperse solutes. A matrix of spreading functions, characterizing the dispersive properties of th e column, was determined by fitting chromatographic data from a series of monodisperse standards with the solution to the transport equation s and interpolating between the fit parameters. A successive approxima tion scheme was used in which a test distribution was incrementally co rrected by an amount proportional to the error between the measured ch romatograph and that derived from the test distribution. A nonlinear r elaxing function was used to constrain the correction term such that t he solution remained physically realizable (i.e., nonnegative absorban ce) as it evolved. Deconvolved chromatographs of Lipoproteins provided resolution of peaks that were obscured by spreading in the original d ata. The distribution of particle sizes within each fraction was calcu lated and verified experimentally by further separating the contents o f fractions by gradient gel electrophoresis. Our technique, however, p rovided comparable resolution of the peaks without the additional expe rimental procedure. (C) 1996 Academic Press, Inc.