MONOCLONAL-ANTIBODIES AGAINST PLASMA PROTEASE INHIBITORS - PRODUCTION AND CHARACTERIZATION OF 15 MONOCLONAL-ANTIBODIES AGAINST HUMAN ANTITHROMBIN-III - RELATION BETWEEN ANTIGENIC DETERMINANTS AND FUNCTIONAL SITES OF ANTITHROMBIN-III

  • 1 January 1985
    • journal article
    • research article
    • Vol. 65  (5) , 1201-1207
Abstract
Fifteen hybridomas secreting monoclonal antibodies against human antithrombin III, originating from 2 mouse strains, were produced by the cell fusion technique. Eight monoclonal antibodies belong to the class IgG1, 5 to the class IgG2a, and 2 to the class IgG2b. All L chains belong to the .kappa. group. No cross-reaction of the monoclonal antibodies was observed with a crude preparation of albumin nor with .alpha.1-antitrypsin and .alpha.2-antiplasmin. Five of these monoclonal antibodies exhibit a relatively high avidity for antithrombin III. Inhibition experiments showed that the 15 monoclonal antibodies define 7 more or less independent antigenic regions on the antithrombin III molecule. Examination of the effects of these antibodies on the inhibitory capacity of antithrombin III toward thrombin activity, either in the presence or in the absence of heparin, showed that several monoclonal antibodies inhibit the antithrombin III activity and allowed to relate some of the antigenic determinants to functional sites on the antithrombin III molecule.