CAPILLARY-ZONE-ELECTROPHORESIS FOR THE STUDY OF THE BINDING OF ANTITHROMBIN TO LOW-AFFINITY HEPARIN

When low-affinity interactions between glycosaminoglycans and precious proteins are studied, it is imperative to design an experimental set- up that consumes as little material as possible. To evaluate the appli cability of the CZE technique to this problem, we explored the interac tion between antithrombin and low-affinity heparin. In a series of CZE experiments we demonstrated that the mobility of antithrombin increas es gradually as increased concentrations of low-affinity heparin were added to the electrolyte. The results were, as expected, consistent wi th the general algorithm for monovalent binding. The binding constant was estimated at 20+/-6 mu M in excellent agreement with the value rep orted in the literature.