Immunoglobulin heavy variable 1-18
1_MDWTW 6_ SILFL 11_ VAAAT 16_ GAHSQ 21_ VQLVQ 26_ SGAEV 31_ KKPGA 36_ SVKVS 41_ CKASG 46_ YTFTS 51_ YGISW 56_ VRQAP 61_ GQGLE 66_ WMGWI 71_ SAYNG 76_ NTNYA 81_ QKLQG 86_ RVTMT 91_ TDTST 96_ STAYM 101_ ELRSL 106_ RSDDT 111_AVYYC
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)