Immunoglobulin lambda variable 5-39
1_MAWTP 6_ LLLLL 11_ LSHCT 16_ GSLSQ 21_ PVLTQ 26_ PTSLS 31_ ASPGA 36_ SARFT 41_ CTLRS 46_ GINVG 51_ TYRIY 56_ WYQQK 61_ PGSLP 66_ RYLLR 71_ YKSDS 76_ DKQQG 81_ SGVPS 86_ RFSGS 91_ KDAST 96_ NAGLL 101_ LISGL 106_ QSEDE 111_ ADYYC 116_AIWYS
1: 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)