title: Induction of autoantibodies to human enzymes following viral infection: a biologically relevant hypothesis.
abstract: Macro enzymes, i.e. complexes of normal (iso-)enzymes with an immunoglobulin, may be due to immunological cross-reactions evoked by specific viral antigenic determinants that are homologous to regions in the target enzymes. A search of the National Biomedical Research Foundation protein databank with the amino-acid sequence of human pancreatic amylase revealed a marked homology with a fragment of the yellow fever virus major envelope protein E: i.e. an overall identity of 19.7 per cent and a high degree (40.9 per cent) of conservative amino-acid substitutions over 119 amino acids. At each identical position, the corresponding residue of Taka amylase A was examined by three-dimensional structure analysis, to determine whether the position is likely to be buried or exposed. The existence of a site (epitope) on amylase recognized by an anti-amylase antibody is discussed.
mesh_terms: D000595:Amino Acid Sequence; D000681:Amylases / Q000737:chemistry* / Q000276:immunology; D001323:Autoantibodies / Q000096:biosynthesis*; D003429:Cross Reactions; D000939:Epitopes; D006801:Humans; D008969:Molecular Sequence Data; D010179:Pancreas / Q000201:enzymology*; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D016415:Sequence Alignment; D014036:Togaviridae Infections / Q000276:immunology; D014759:Viral Envelope Proteins / Q000737:chemistry* / Q000276:immunology; D014777:Virus Diseases / Q000276:immunology*; D015005:Yellow fever virus / Q000276:immunology*
chemical_list: D001323:Autoantibodies; D000939:Epitopes; D014759:Viral Envelope Proteins; C078400:yellow fever virus envelope protein E; D000681:Amylases