Immunoglobulin heavy constant alpha 2 (Ig alpha-2 chain C region) (Ig alpha-2 chain C region BUT) (Ig alpha-2 chain C region LAN)
1_ASPTS 6_ PKVFP 11_ LSLDS 16_ TPQDG 21_ NVVVA 26_ CLVQG 31_ FFPQE 36_ PLSVT 41_ WSESG 46_ QNVTA 51_ RNFPP 56_ SQDAS 61_ GDLYT 66_ TSSQL 71_ TLPAT 76_ QCPDG 81_ KSVTC 86_ HVKHY 91_ TNSSQ 96_ DVTVP 101_ CRVPP 106_ PPPCC 111_ HPRLS 116_ LHRPA 121_ LEDLL 126_ LGSEA 131_ NLTCT 136_ LTGLR 141_ DASGA 146_ TFTWT 151_ PSSGK 156_ SAVQG 161_ PPERD 166_ LCGCY 171_ SVSSV 176_ LPGCA 181_ QPWNH 186_ GETFT 191_ CTAAH 196_ PELKT 201_ PLTAN 206_ ITKSG 211_ NTFRP 216_ EVHLL 221_ PPPSE 226_ ELALN 231_ ELVTL 236_ TCLAR 241_ GFSPK 246_ DVLVR 251_ WLQGS 256_ QELPR 261_ EKYLT 266_ WASRQ 271_ EPSQG 276_ TTTYA 281_ VTSIL 286_ RVAAE 291_ DWKKG 296_ ETFSC 301_ MVGHE 306_ ALPLA 311_ FTQKT 316_ IDRMA 321_ GKPTH 326_ INVSV 331_VMAEA
1: Constant region of immunoglobulin heavy 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). Ig alpha is the major immunoglobulin class in body secretions (PubMed:2241915)