Novel cross-linking agents for hydrogelation of biological polymers

Cross-linking agents are useful for investigating the biological functions of biological polymers. Here we would like to report the preparation of a 4-hydroxyphenyldimethyl-sulfoniummethylsulfate (DSP) activated cross-linker that can cross-link proteins as a novel cross-linking agent. By using this cross-linker, gelatin can be cross-linked both in the sol-state at 40°C and in the gel-state at 2°C. The chemically cross-linked gelatin gels by DSP-activated esters that were obtained in gel-state and sol-state at a gelatin concentration greater than 1% and 5%, respectively. The fixed conformation of the folding structure seen with this physical cross-linking system is thought to result from the structure of the native protein. In addition, the urea concentration dependence of the swelling ratio indicates that the hydrogen bonds are much more stable in the gel prepared from the gel state of gelatin than those in the gel prepared from the sol state of gelatin. As a result, these novel bifunctional agents of the hydrogelation of biological polymers are expected to have applications in studying intermolecular interaction.