[Immobilization of trypsin on polyurethane carriers].

A method of covalent immobilization of trypsin on polyurethanes containing residues of 2.4-toluene or hexamethylene diisocyanates in a side chain is developed. It is shown that the amount of the immobilized enzyme is independent of isocyanate nature, but its proteolytic activity is higher on carriers containing 2.4-toluene diisocyanate residues. This is accounted for by higher mobility of enzyme molecules due to a decrease in the number of chemical bonds between trypsin and the polymer matrix. The immobilized enzyme is stable for a long time and does not lose proteolytic activity being cyclically used for many times.