Immunoglobulin heavy variable 3-64
1_MMEFG 6_ LSWVF 11_ LVAIF 16_ KGVQC 21_ EVQLV 26_ ESGEG 31_ LVQPG 36_ GSLRL 41_ SCAAS 46_ GFTFS 51_ SYAMH 56_ WVRQA 61_ PGKGL 66_ EYVSA 71_ ISSNG 76_ GSTYY 81_ ADSVK 86_ GRFTI 91_ SRDNS 96_ KNTLY 101_ LQMGS 106_ LRAED 111_MAVYY
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)