Premium
Modulation of antibody binding affinity by somatic mutation
Author(s) -
Allen Deborah,
Cumano Ana,
Simon Thomas,
Sablitzky Fred,
Rajewsky Klaus
Publication year - 1988
Publication title -
international journal of cancer
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.475
H-Index - 234
eISSN - 1097-0215
pISSN - 0020-7136
DOI - 10.1002/ijc.2910410802
Subject(s) - hapten , antibody , immunoglobulin light chain , affinity maturation , microbiology and biotechnology , point mutation , mutation , immunoglobulin heavy chain , monoclonal antibody , mutagenesis , biology , germline mutation , immunoglobulin idiotypes , antigen , recombinant dna , monoclonal , genetics , gene
The affinity of hapten binding of monoclonal antibodies (M Abs) specific for 4‐hydroxy‐3‐nitrophtmyl acetyl (NP) has been investigated at the molecular level by both site‐specific mutagenesis and recombinant antibody construction, followed by expression in myeloma cells. We have shown that a single point mutation (trp→leu at codon 33) in the variable region of the heavy chain (V H ) is sufficient to endow a primary‐response, germline‐encoded antibody with an affinity for antigen typical of a secondary‐response antibody carrying the same mutation. We have also demonstrated that mutations additional to the trp → leu exchange in the heavy chain and further mutations in the light chain are irrelevant to the high‐affinity phenotype of secondary‐response antibodies. Since some of these are “parallel” mutations common to clonally unrelated antibodies, this suggests that the mutation rate is not constant across the entire immunoglobulin variable region. Although antibodies with a trp → leu exchange at position 33 are positively selected because of improved hapten binding affinity, we have found that, under rare circumstances, other patterns of mutations may be selected through particular D‐J H combinations; we have demonstrated one case where this has generated an antibody with very efficient hapten binding ability.