Primary structure of the human M2 mitochondrial autoantigen of primary biliary cirrhosis: dihydrolipoamide acetyltransferase

Proc Natl Acad Sci U S A. 1988 Oct;85(19):7317-21. doi: 10.1073/pnas.85.19.7317.


Primary biliary cirrhosis is a chronic, destructive autoimmune liver disease of humans. Patient sera are characterized by a high frequency (greater than 95%) of autoantibodies to a Mr 70,000 mitochondrial antigen, a component of the M2 antigen complex. We have identified a human cDNA clone encoding the complete amino acid sequence of this autoantigen. The predicted structure has significant similarity with the dihydrolipoamide acetyltransferase (EC of the Escherichia coli pyruvate dehydrogenase multienzyme complex. The human sequence preserves the Glu-Thr-Asp-Lys-Ala motif of the lipoyl-binding site and has two potential binding sites. Expressed fragments of the cDNA react strongly with sera from patients with primary biliary cirrhosis but not with sera from patients with autoimmune chronic active hepatitis or sera from healthy subjects.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Acetyltransferases / analysis*
  • Acetyltransferases / genetics
  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • DNA / analysis
  • Dihydrolipoyllysine-Residue Acetyltransferase
  • Humans
  • Liver Cirrhosis, Biliary / enzymology*
  • Molecular Sequence Data
  • Molecular Weight
  • Pyruvate Dehydrogenase Complex*
  • Rats


  • Pyruvate Dehydrogenase Complex
  • DNA
  • Acetyltransferases
  • Dihydrolipoyllysine-Residue Acetyltransferase

Associated data

  • GENBANK/J03866