Immunoglobulin lambda variable 2-18
1_MAWAL 6_ LLLTL 11_ LTQGT 16_ GSWAQ 21_ SALTQ 26_ PPSVS 31_ GSPGQ 36_ SVTIS 41_ CTGTS 46_ SDVGS 51_ YNRVS 56_ WYQQP 61_ PGTAP 66_ KLMIY 71_ EVSNR 76_ PSGVP 81_ DRFSG 86_ SKSGN 91_ TASLT 96_ ISGLQ 101_ AEDEA 106_ DYYCS 111_LYTSS
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)