title: Monoclonal antibody to fibrin D-dimer (DD-3B6) recognizes an epitope on the gamma-chain of fragment D.
abstract: Laboratory determination of fibrinolysis has been facilitated by diagnostic tests that use monoclonal antibody DD-3B6 to measure fibrin D-dimer levels in plasma. When DD-3B6 is reacted with soluble fibrin fragments, it is specific for fragment D-dimer. The authors have used immunoblot analysis of DD-3B6 binding to purified fragment D and fragment D-dimer to localize the binding site of the antibody. Although DD-3B6 recognizes only fragment D-dimer in solution, it binds to both immobilized fragment D-dimer and fragment D in immunoblots. When immunoblots were performed using protein which was electrophoresed under reducing conditions, DD-3B6 bound to the gamma-chain of fragments D1, D2, and D3. Therefore, the epitope recognized by DD-3B6 resides between amino acids 86 and 302 in the gamma-chain of fragment D. This epitope is masked in soluble non-cross-linked or nondegraded fibrin, but becomes expressed after cross-linked fibrin has been cleaved by plasmin.
mesh_terms: D000911:Antibodies, Monoclonal; D001666:Binding Sites, Antibody; D004591:Electrophoresis, Polyacrylamide Gel; D000939:Epitopes / Q000032:analysis*; D005338:Fibrin Fibrinogen Degradation Products / Q000276:immunology*; D006801:Humans; D007120:Immunochemistry; D008970:Molecular Weight; D010084:Oxidation-Reduction
chemical_list: D000911:Antibodies, Monoclonal; D000939:Epitopes; D005338:Fibrin Fibrinogen Degradation Products; C036309:fibrin fragment D