Thermal Stability of Immobilized Enzymes Circular Dichroism, Fluorescence and Kinetic Measurements of α‐Chymotrypsin Attached to Soluble Carriers

The temperature‐induced unfolding of α‐chymotrypsin and of chymotrypsin covalently bound to two soluble transparent carriers, dextran and a copolymer of maleic acid anhydride and acrylic acid, has been studied by tryptophan fluorescence emission, circular dichroic and kinetic measurements. It has been shown that the structural and functional properties of the enzyme when bound to the anionic copolymer are strongly influenced by electrostatic interactions. A number of reference experiments with anionic polyelectrolytes and the hydrogenated monomers of the copolymer suggest that these changes are brought about by the cooperative ion pair formation between protein and polyanionic matrix.