Planar chromatographic and electrophoretic study of thermally induced conformational modifications of protein structure

Abstract

It is well known that the structure of BSA explains its capacity to interact both hydrophobically and hydrophilically with other biochemical species. In the native state the BSA molecule takes such a conformation that the polar residues of amino-acids are oriented towards the outside the molecule and the non-polar residues are directed prevalently towards the inside of the molecule. The main effect of heat on the conformation of the albumin is supposed to consist in the redirection of the amino acid moieties which involves a change in the hydrophobic–hydrophilic balance. A sequence of conformational modifications is assumed to result from different refolding processes of thermally denatured BSA. This leads, because of the large number of degrees of freedom of the macromolecule, from the largely featureless ensemble of denatured conformations to structures modified do different extents compared with the one structure of the native albumin molecule [1]. In this way the capacity of the protein to interact or bind with other species is modified, as is well observed in its chromatographic and electrophoretic behavior. Our paper deals with use of these techniques to study the effect of the refolding process on thermally denatured BSA.