Affinity capillary electrophoresis employing immobilized glycosaminoglycan to resolve heparin-binding peptides

A new capillary electrophoresis technique has been developed for the affinity resolution of synthetic heparin-binding peptides using an immobilized glycosaminoglycan. Heparin and heparan sulfate were immobilized onto fused silica capillaries using biotin-neutravidin conjugation. These capillaries exhibited markedly reduced electroosmotic flow and were able to distinguish peptides based on the heparin binding domain of acidic fibroblast growth factor (residues 125-144, GLKKNGSCKRGPRTHYGQKA) that differed only in the stereochemistry of the proline amino acid residue. The peptide based on the native sequence was retarded compared to the peptide having unnatural stereochemistry, consistent with its stronger interaction for immobilized glycosaminoglycan. Improved resolution is also obtained for additional arginine and lysine containing heparin-binding peptides.