title: Evolution of immunoglobulin polypeptide chains: carboxy-terminal of an IgM heavy chain.
abstract: The dipeptide sequence at the carboxy-terminal of a heavy (micro) chain from a human macroglobulin ( IgM) is tyrosylcysteine, although the reverse sequence, cysteinyltyrosine, has not been rigorously excluded. The presence of cysteine at the carboxy-terminal was predicted from a recognition of the chemical homologies among the polypeptide chains of immunoglobulins, and their probable evolutionary origin.
mesh_terms: D000595:Amino Acid Sequence; D002247:Carbon Isotopes; D003545:Cysteine / Q000032:analysis*; D006801:Humans; D014443:Tyrosine / Q000032:analysis*; D005719:gamma-Globulins / Q000032:analysis*
chemical_list: D002247:Carbon Isotopes; D005719:gamma-Globulins; D014443:Tyrosine; D003545:Cysteine