Mass spectrometry-based molecular mapping of native FXIIIa cross-links in insoluble fibrin clots

J Biol Chem. 2019 May 31;294(22):8773-8778. doi: 10.1074/jbc.AC119.007981. Epub 2019 Apr 26.


The roles of factor XIIIa-specific cross-links in thrombus formation, regression, or probability for embolization are largely unknown. A molecular understanding of fibrin architecture at the level of these cross-links could inform the development of therapeutic strategies to prevent the sequelae of thromboembolism. Here, we present an MS-based method to map native factor XIIIa cross-links in the insoluble matrix component of whole-blood or plasma-fibrin clots and in in vivo thrombi. Using a chaotrope-insoluble digestion method and quantitative cross-linking MS, we identified the previously mapped fibrinogen peptides that are responsible for covalent D-dimer association, as well as dozens of novel cross-links in the αC region of fibrinogen α. Our findings expand the known native cross-linked species from one to over 100 and suggest distinct antiparallel registries for interprotofibril association and covalent attachment of serpins that regulate clot dissolution.

Keywords: chemical digestion; factor XIII; fibrin; fibrinolysis; mass spectrometry (MS); protein cross-linking; thrombosis; transglutaminase.

Publication types

  • Research Support, N.I.H., Extramural

MeSH terms

  • Amino Acid Sequence
  • Chromatography, High Pressure Liquid
  • Factor XIIIa / chemistry*
  • Factor XIIIa / metabolism
  • Fibrin / chemistry*
  • Fibrin Fibrinogen Degradation Products / chemistry
  • Fibrinogen / chemistry
  • Humans
  • Lysine / chemistry
  • Mass Spectrometry
  • Peptide Mapping / methods*
  • Peptides / analysis*
  • Thrombosis / metabolism
  • Thrombosis / pathology


  • Fibrin Fibrinogen Degradation Products
  • Peptides
  • fibrin fragment D
  • fibrinogen Aalpha
  • Fibrin
  • Fibrinogen
  • Factor XIIIa
  • Lysine

Associated data

  • PDB/3GHG