NCIt definition : Complement C3d (302 aa, 34 kDa) is encoded by the human C3 gene. This protein is
involved in the promotion of B-cell and complement activation.;
Alternative definition : CDISC: An antigen of the cleaved d fragment of the C3 complement protein. It can be
considered as an autoantigen and is commonly associated with the autoimmune disease
systemic lupus erythematosus.;
NCIt note : C3d is comprised of amino acids 1002-1303 of the complement C3 protein and is produced
through proteolysis of C3 into an alpha chain (C3a) and a beta chain (C3b) followed
by further proteolysis and inactivation of C3b. (UniProt);