USE OF CAPILLARY ZONE ELECTROPHORESIS FOR THE ANALYSIS OF DNA-BINDING TO A PEPTIDE DERIVED FROM AMYLOID P COMPONENT

Capillary zone electrophoresis was used to characterize the binding interactions between oligonucleotides and synthetic peptides derived from human serum amyloid P component. From a solution containing free and peptide-bound oligonucleotides, free nucleotide was separated from the complex by means of electrophoresis. In this way, both qualitative and quantitative aspects of the binding could be assessed rapidly using minute amounts of unlabelled samples. Minimal structures and sequence specificity of binding of nucleotides and peptides could be characterized and, based on the quantitative output of the electrophoretic analysis, binding constants were estimated. In theory, the approach is applicable for any molecular interaction where the charge/mass ratio of complexes differ from the free molecules and where at least one of the interacting components is quantitatively recoverable and detectable in the capillary electrophoresis system. As such, it is the only method available for simple and fast estimates of binding parameters for unlabelled low molecular weight compounds in solution.