Anti-Mouse Complement component 4d (C4d) Polyclonal Antibody-10 mg (CAT#: CB-P545-K) Datasheet

Antibody

The polyclonal antibody recognizes mouse C4d. Complement factor C4 (MW 41 kDa), formerly known as Gg protein, is composed of α, β and γ chains. The classical pathway of complement and the mannose-binding lectin (MBL) activation pathway converge at C4. Activated C1, MASP-1 and MASP-2 cleave C4, resulting in the formation of C4a and C4b. The latter can be cleaved by factor I to produce C4c and C4d, all functional sites are lost in this step. The C4d activation fragment of C4 is an excellent marker for the activation of the classical complement pathway and MBL pathway. The thioester formed between the side chains of Cys1010 and Gln1013 in the C4d region of the α chain mediates covalent attachment to the target surface with activated form of C1s or MASP. In addition, C4d is highly homologous to C3d, which has more than 35% shared amino acid sequence. In many diseases, such as rheumatoid arthritis (RA), hereditary angioedema (HAE), systemic lupus erythematosus (SLE) and chronic urticaria, the high complement level of C4d in serum or plasma is significantly increased. C4d levels in the plasma of patients with various humoral autoimmune diseases may also increase, and it is known that complement activation occurs. The deposition of C4d in the capillaries around the renal tubules has been shown to be a sensitive marker of antibody-mediated (humoral) rejection in renal transplantation biopsy.