[That region of the immunoglobulin molecule that varies in its amino acid sequence and composition, and comprises the binding site for a specific antigen. It is located at the N-terminus of the Fab fragment of the immunoglobulin. It includes hypervariable regions (COMPLEMENTARITY DETERMINING REGIONS) and framework regions. ( MSH )]
UMLS (NCI) C0877857 - Amino Acid, Peptide, or Protein
- Immunologic Factor