Immunoglobulin heavy constant alpha 1 (Ig alpha-1 chain C region) (Ig alpha-1 chain C region BUR) (Ig alpha-1 chain C region TRO)
1_ASPTS 6_ PKVFP 11_ LSLCS 16_ TQPDG 21_ NVVIA 26_ CLVQG 31_ FFPQE 36_ PLSVT 41_ WSESG 46_ QGVTA 51_ RNFPP 56_ SQDAS 61_ GDLYT 66_ TSSQL 71_ TLPAT 76_ QCLAG 81_ KSVTC 86_ HVKHY 91_ TNPSQ 96_ DVTVP 101_ CPVPS 106_ TPPTP 111_ SPSTP 116_ PTPSP 121_ SCCHP 126_ RLSLH 131_ RPALE 136_ DLLLG 141_ SEANL 146_ TCTLT 151_ GLRDA 156_ SGVTF 161_ TWTPS 166_ SGKSA 171_ VQGPP 176_ ERDLC 181_ GCYSV 186_ SSVLP 191_ GCAEP 196_ WNHGK 201_ TFTCT 206_ AAYPE 211_ SKTPL 216_ TATLS 221_ KSGNT 226_ FRPEV 231_ HLLPP 236_ PSEEL 241_ ALNEL 246_ VTLTC 251_ LARGF 256_ SPKDV 261_ LVRWL 266_ QGSQE 271_ LPREK 276_ YLTWA 281_ SRQEP 286_ SQGTT 291_ TFAVT 296_ SILRV 301_ AAEDW 306_ KKGDT 311_ FSCMV 316_ GHEAL 321_ PLAFT 326_ QKTID 331_ RLAGK 336_ PTHVN 341_ VSVVM 346_AEVDG
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)