Complement Component Protein One of a group of about 20 proteins that is found in the blood and is important in fighting infections and other diseases. Complement Component Protein Any of the serum proteins that interact with antigen antibody complex to produce cytolytic, chemotaxic, anaphylactic, and other effects. (from CSP2000) C21523 Complement_Component_Protein complement protein Amino Acid, Peptide, or Protein C0312743 Complement Component Protein Blood Proteins