[Smaller fragment formed when C5 convertase splits C5 into C5a and C5b. C5a is a 74-amino acid peptide that includes a carboxy-terminal arginine crucial for its spasmogenic activity and a carbohydrate moiety. Initiates the spontaneous assembly of the late complement components, C5-C9, into the membrane attack complex. C5a is the most potent anaphylatoxin, mediating immediate hypersensitivity. C5a is also chemotactic for neutrophils and monocytes. ( NCI )]
UMLS (NCI) C0009521 - Amino Acid, Peptide, or Protein
- Immunologic Factor