C9 Antibody (Polyclonal)

A goat antiserum raised against human C9 protein.

> 40 mg/mL

Goat

Short term (30 days) 4˚C. Long term at or below –20˚C.

C9 is a glycoprotein which is present in normal human serum/plasma at approximately 55 µg/mL. Primarily synthesized in the liver, C9 is a single-chain protein with a molecular weight of approximately 71 kD. This complement protein is amphiphilic in nature, and can be fragmented by human α-thrombin to produce C9a and C9b. The hydrophilic domain of the C9 complex becomes the C9a fragment and has an approximate molecular weight of 34 kD. The hydrophobic end becomes C9b fragment, which has an approximate molecular weight of 37 kD. With activation of the classical or alternative pathways of the complement system, C5 convertase cleaves the C5 chain into C5a and C5b. C5b remains bound to the convertase and will combine with C6 to form a C5b,6 complex. This complex normally interacts with C7 to form C5b,6,7 that becomes partially embedded in the target cell outer membrane. The C5b,6,7 complex will subsequently bind C8 and multiple C9 molecules completing the terminal pathway. The binding of C8 increases the hydrophobic binding sites expressed in the complex. Increased hydrophobicity results in the partial insertion of the C5b-8 complex into the interior of the target cell membrane bilayer. Further binding of the C9 molecules increases the hydrophobicity of the entire C5b-9 complex, which results in the disruption of the membrane structure and causes irreversible loss of membrane function. The C5b,6,7,8,9, or C5b-9 complex, is also known as the Membrane Attack Complex (MAC), which causes irreversible damage to the target cell membrane.