beta-Hydroxyaspartic acid in vitamin K-dependent protein C

Proc Natl Acad Sci U S A. 1983 Apr;80(7):1802-6. doi: 10.1073/pnas.80.7.1802.


Previous work has shown that the light chain of protein C, an anticoagulant plasma protein, contains an unusual amino acid [Fernlund, P. & Stenflo, J. (1982) J. Biol. Chem. 257, 12170-12179]. To determine the structure of this amino acid a heptapeptide, CMCys-Ile-X-Gly-Leu-Gly-Gly (residues 69-75 in the light chain), was isolated from enzymatic digests of the light chain. According to automatic Edman sequence analysis, 1H NMR spectroscopy, and mass spectrometry the heptapeptide had beta-hydroxyaspartic acid in its third position, which corresponds to position 71 in the light chain of protein C. Analysis of acid and aminopeptidase M hydrolysates of the heptapeptide showed the beta-hydroxyaspartic acid to be the erythro form. Acid hydrolysis of protein C released approximately equal to 1 mol of beta-hydroxyaspartic acid per mol of protein. The function of this amino acid, which, to the best of our knowledge, has not been found previously in proteins, is unknown.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Aspartic Acid / analogs & derivatives*
  • Blood Coagulation Factors*
  • Cattle
  • Glycoproteins*
  • Magnetic Resonance Spectroscopy
  • Mass Spectrometry
  • Peptide Fragments / analysis
  • Protein C
  • Vitamin K


  • Blood Coagulation Factors
  • Glycoproteins
  • Peptide Fragments
  • Protein C
  • Vitamin K
  • Aspartic Acid