Interaction Between The Collagen Peptide And The Binary Organic Ionic Salts

Collagen peptide was one of a polypeptide chain obtained from physical andchemical degradation of collagen, which belongs to the typical amphotericpolyelectrolytes. Because of the polar functional group and non-polar functional groupin the side chain, the polar functional group divided into acidic, alkaline and neutralgroup. The alkaline group contains-NH₂,-NH-, and the acidic group was–COO^-. Wesystem designed a series of binary organic ionic compounds which can cross-linksthrough ionic bonds with both free anions and cation groups of collagen. The maingroups of ionic compounds are quaternary ammonium ions and sulfonate ions, wherequaternary ammonium ions cross-link with free carboxyl of peptide chain primarily andsulfonate ions cross-links with free amino of peptide chain. In order to verify thebinary ionic compounds combined with collagen peptides with two points, weprepared the corresponding single ionic functional groups compounds to make acomparison, we also studied the effect of ionic compounds to the viscosity of collagenpeptide in different temperature, PH and molar ratio. The test of viscosity and thechange of aqueous fluorescence verified the formation of ionic bonds between binarysalt organic ions and the free functional groups on collagen polypeptide chain. Thexerogel was prepared by collagen polypeptide aqueous solution with binary organic saltadded in. The result of DSC showed that the thermal stability of aerogels increasedobviously, and swelling analysis also displayed that the water absorption ratio reducedafter cross-linking. The increase of thermal stability and reduce of water absorptionratio can attributed to the more stabilized of conformation of collagen protein after thecross-linking of ionic compounds and collagen protein.