complementarity-determining region

initialism: CDR
https://doi.org/10.1351/goldbook.13029
Hypervariable amino acid sequence within antibody and T-cell receptor (TCR) variable (V) regions, which interacts with complementary amino acids on the antigen or major histocompatibility complex (MHC)–peptide complex.
Source:
PAC, 2012, 84, 1113. (IUPAC glossary of terms used in immunotoxicology (IUPAC Recommendations 2012)) on page 1147 [Terms] [Paper]