Immunoglobulin lambda variable 3-9
1_MAWTA 6_ LLLSL 11_ LAHFT 16_ GSVAS 21_ YELTQ 26_ PLSVS 31_ VALGQ 36_ TARIT 41_ CGGNN 46_ IGSKN 51_ VHWYQ 56_ QKPGQ 61_ APVLV 66_ IYRDS 71_ NRPSG 76_ IPERF 81_ SGSNS 86_ GNTAT 91_ LTISR 96_ AQAGD 101_ EADYY 106_CQVWD
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)