title: Monoclonal anti-human C3d antibodies: stabilization of the alternative pathway C3 convertase.
abstract: IgG mouse monoclonal antibody (mAb) was prepared by fusion of spleen cells from mice immunized with human C3d (mAb:C3d) using syngeneic thymocytes as feeder cells. mAb:C3d was assessed for its effect on the stabilization of the cell-bound alternative pathway C3 convertase EAC3bBb. It bound to cell-bound C3b and stabilized C3bBb at 30 degrees in the presence of EDTA-GVB. The plasma protein H reduced the stabilization effect of the stabilized C3 convertase. These results suggest that binding of antibody to C3d may stabilize C3bBb. It seems likely that such antibody induces in C3b conformational change, which increases the C3bBb complex stability.
authors.affiliation: Second Department of Internal Medicine, Nihon University, Tokyo, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Tanuma
authors.forename: H
authors.initials: H
authors.lastname: Ohi
authors.forename: M
authors.initials: M
authors.lastname: Hatano
mesh_terms: D000911:Antibodies, Monoclonal / Q000494:pharmacology*; D003166:Complement Activating Enzymes / Q000276:immunology*; D003167:Complement Activation; D003178:Complement C3 Nephritic Factor / Q000494:pharmacology; D050577:Complement C3-C5 Convertases / Q000276:immunology*; D003180:Complement C3b Inactivator Proteins / Q000494:pharmacology; D015933:Complement C3d / Q000276:immunology*; D017242:Complement Factor H; D003170:Complement Pathway, Alternative; D004795:Enzyme Stability; D006801:Humans; D007074:Immunoglobulin G / Q000494:pharmacology
chemical_list: D000911:Antibodies, Monoclonal; C493495:CFH protein, human; D003178:Complement C3 Nephritic Factor; D003180:Complement C3b Inactivator Proteins; D007074:Immunoglobulin G; D015933:Complement C3d; D017242:Complement Factor H; D003166:Complement Activating Enzymes; D050577:Complement C3-C5 Convertases