抄録
The stability of immobilized human urokinase (UK; EC 3.4.21.31) is an important factor for the clinical application of the enzyme as an antithrombotic material. The stabilities of human UK immobilized on a polymeric support to heat and enzyme inhibitors were compared with those of the original soluble UK.UK was immobilized on an ethylene vinyl acetate copolymer (EVA) tube which has maleic anhydride as a functional group on its surface. Immobilized UK showed greater stability to thermal degradation than soluble UK. Comparative kinetic studies of these two forms of UK toward enzyme inhibitors revealed that immobilization of the enzyme did not result in any change of Michaelis constants (Km), though a significant increase of inhibition constans (Ki) was observed.Furthermore, UK immobilized on the EVA tube showed resistance to thermal denaturation. Therefore, an EVA tube carrying immobilized UK represents a stable and easy-to-handle material for clinical use.
