Immunoglobulin lambda constant 7 (Ig lambda-7 chain C region)
1_GQPKA 6_ APSVT 11_ LFPPS 16_ SEELQ 21_ ANKAT 26_ LVCLV 31_ SDFNP 36_ GAVTV 41_ AWKAD 46_ GSPVK 51_ VGVET 56_ TKPSK 61_ QSNNK 66_ YAASS 71_ YLSLT 76_ PEQWK 81_ SHRSY 86_ SCRVT 91_ HEGST 96_ VEKTV 101_APAEC
1: Constant region of immunoglobulin light chains. 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)