3upa | pdb_00003upa
A general strategy for the generation of human antibody variable domains with increased aggregation resistance
Structural highlights
FunctionKV139_HUMAN V region of the variable domain of immunoglobulin light chains that participates in the antigen recognition (PubMed:24600447). Immunoglobulins, also known as antibodies, are membrane-bound or secreted glycoproteins produced by B lymphocytes. In the recognition phase of humoral immunity, the membrane-bound immunoglobulins serve as receptors which, upon binding of a specific antigen, trigger the clonal expansion and differentiation of B lymphocytes into immunoglobulins-secreting plasma cells. Secreted immunoglobulins mediate the effector phase of humoral immunity, which results in the elimination of bound antigens (PubMed:20176268, PubMed:22158414). The antigen binding site is formed by the variable domain of one heavy chain, together with that of its associated light chain. Thus, each immunoglobulin has two antigen binding sites with remarkable affinity for a particular antigen. The variable domains are assembled by a process called V-(D)-J rearrangement and can then be subjected to somatic hypermutations which, after exposure to antigen and selection, allow affinity maturation for a particular antigen (PubMed:17576170, PubMed:20176268).[1] [2] [3] [4] Publication Abstract from PubMedThe availability of stable human antibody reagents would be of considerable advantage for research, diagnostic, and therapeutic applications. Unfortunately, antibody variable heavy and light domains (V(H) and V(L)) that mediate the interaction with antigen have the propensity to aggregate. Increasing their aggregation resistance in a general manner has proven to be a difficult and persistent problem, due to the high level of sequence diversity observed in human variable domains and the requirement to maintain antigen binding. Here we outline such an approach. By using phage display we identified specific positions that clustered in the antigen binding site (28, 30-33, 35 in V(H) and 24, 49-53, 56 in V(L)). Introduction of aspartate or glutamate at these positions endowed superior biophysical properties (non-aggregating, well-expressed, and heat-refoldable) onto domains derived from common human germline families (V(H)3 and V(kappa)1). The effects of the mutations were highly positional and independent of sequence diversity at other positions. Moreover, crystal structures of mutant V(H) and V(L) domains revealed a surprising degree of structural conservation, indicating compatibility with V(H)/V(L) pairing and antigen binding. This allowed the retrofitting of existing binders, as highlighted by the development of robust high affinity antibody fragments derived from the breast cancer therapeutic Herceptin. Our results provide a general strategy for the generation of human antibody variable domains with increased aggregation resistance. General strategy for the generation of human antibody variable domains with increased aggregation resistance.,Dudgeon K, Rouet R, Kokmeijer I, Schofield P, Stolp J, Langley D, Stock D, Christ D Proc Natl Acad Sci U S A. 2012 Jul 3;109(27):10879-84. Epub 2012 Jun 27. PMID:22745168[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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