Heparin-like tubings. II. Mechanism of the thrombin-antithrombin III reaction at the surface.

ABSTRACT

In a previous paper we described the surface treatment of tubings made of polystyrene grafted by irradiation onto polyethylene tubular materials. As a result, polystyrene moieties of their inner face were substituted by sulphonate and aspartic acid sulphamide groups. In order to study the mechanism of the thrombin-antithrombin III reaction occurring at the modified surface and to determine the kinetics of the reaction, step by step experiments were set up involving either the protease adsorbed at the surface reacting with the antiprotease circulating in the solution or the opposite. These procedures allowed us to demonstrate the heparin-like catalytic activity of the tubings.