Use of capillary zone electrophoresis to evaluate the binding of anionic carbohydrates to synthetic peptides derived from human serum amyloid P component

• Published in: Analytical chemistry (Washington) Vol. 64; no. 21; pp. 2479 - 2482
• Main Authors: Heegaard, Niels H. H, Robey, Frank A
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.11.1992
• Subjects: Amino Acid Sequence; Analytical, structural and metabolic biochemistry; Anions; Biological and medical sciences; Carbohydrate Metabolism; Electrophoresis - methods; Fundamental and applied biological sciences. Psychology; General aspects, investigation methods; Humans; Molecular Sequence Data; Peptide Fragments - chemical synthesis; Peptide Fragments - metabolism; Protein Binding; Proteins; Serum Amyloid A Protein - metabolism; Ligand binding; Zone electrophoresis; Synthetic product; Serum amyloid protein SAP; Investigation method; Peptides; Capillary tube
• ISSN: 0003-2700; 1520-6882
• DOI: 10.1021/ac00045a004

Capillary zone electrophoresis was used to study interactions between anionic carbohydrates and synthetic peptides derived from the heparin-binding region of human serum amyloid P component. The method involves quantitation of unbound peptides after a charge-dependent electrophoretic separation of the peptide-carbohydrate mixture. The concentrations of free peptide were determined by extrapolating the obtained peak areas of the peptide in the presence of ligand to a standard curve. Dissociation constants in the 10(-5) M range were determined, and differences in binding affinity of various peptide modifications were illustrated. The assay requires minute amounts of material (sample volume is 7-15 nL), and as long as the reactants are soluble at the chosen conditions, no modifications or special characteristics of the interacting molecules are needed for their identification. It should be possible to use electrophoretic separation in capillaries to evaluate the binding of peptides to any ligand as long as the differences in charge/mass ratio between free and complexed peptide are of a sufficient magnitude as in the peptide-heparin binding demonstrated here.