Activation and fragmentation of the third (C3) and the fourth (C4) components of complement: generation and isolation of physiologically relevant fragments C3c and C4c.
The degree of the activation and fragmentation of C4 and C3, including chain structure of the activation products, was evaluated by SDS-PAGE analysis of the C4 or C3 antigens that were withdrawn from the reaction media with appropriate immunoadsorbent beads. Full activation of C4 and C3, and subsequent quantitative conversion of C4b into C4c, and C3b into iC3b took place in fresh NHS after the activation of complement with both aggIgG and CVF. For complete conversion of iC3b to C3c erythrocytes carrying the C3b receptor were added to the already activated serum. Both C4c and C3c were isolated by a 2-step procedure involving (i) an adsorption to and (ii) electrophoretic desorption from the respective immunoadsorbent beads.
D003167:Complement Activation; D003176:Complement C3 / Q000302:isolation & purification / Q000378:metabolism*; D015932:Complement C3c; D003181:Complement C4 / Q000302:isolation & purification / Q000378:metabolism*; D015935:Complement C4b; D004220:Disulfides; D004591:Electrophoresis, Polyacrylamide Gel; D004912:Erythrocytes / Q000276:immunology; D006801:Humans; D008970:Molecular Weight; D010446:Peptide Fragments
D003176:Complement C3; D003181:Complement C4; D004220:Disulfides; D010446:Peptide Fragments; C033860:complement C4c; D015932:Complement C3c; D015935:Complement C4b