Immunoglobulin heavy variable 3-49
1_MEFGL 6_ SWVFL 11_ VAILK 16_ GVQCE 21_ VQLVE 26_ SGGGL 31_ VQPGR 36_ SLRLS 41_ CTASG 46_ FTFGD 51_ YAMSW 56_ VRQAP 61_ GKGLE 66_ WVGFI 71_ RSKAY 76_ GGTTE 81_ YAASV 86_ KGRFT 91_ ISRDD 96_ SKSIA 101_ YLQMN 106_ SLKTE 111_DTAVY
1: V region of the variable domain of immunoglobulin heavy 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)