Immunoglobulin kappa variable 1D-16 (Ig kappa chain V-I region HK146) (Ig kappa chain V-I region HK189)
1_MDMRV 6_ LAQLL 11_ GLLLL 16_ CFPGA 21_ RCDIQ 26_ MTQSP 31_ SSLSA 36_ SVGDR 41_ VTITC 46_ RASQG 51_ ISSWL 56_ AWYQQ 61_ KPEKA 66_ PKSLI 71_ YAASS 76_ LQSGV 81_ PSRFS 86_ GSGSG 91_ TDFTL 96_ TISSL 101_ QPEDF 106_ ATYYC 111_QQYNS
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)