Peptide substrate profiling defines fibroblast activation protein as an endopeptidase of strict Gly(2)-Pro(1)-cleaving specificity

FEBS Lett. 2006 Mar 6;580(6):1581-6. doi: 10.1016/j.febslet.2006.01.087. Epub 2006 Feb 3.

Abstract

Fibroblast activation protein (FAP) is a serine protease of undefined endopeptidase specificity implicated in tumorigenesis. To characterize FAP's P(4)-P(2)(') specificity, we synthesized intramolecularly quenched fluorescent substrate sets based on the FAP cleavage site in alpha(2)-antiplasmin (TSGP-NQ). FAP required substrates with Pro at P(1) and Gly or d-amino acids at P(2) and preferred small, uncharged amino acids at P(3), but tolerated most amino acids at P(4), P(1)(') and P(2)('). These substrate preferences allowed design of peptidyl-chloromethyl ketones that inhibited FAP, but not the related protease, dipeptidyl peptidase-4. Thus, FAP is a narrow specificity endopeptidase and this can be exploited for inhibitor design.

MeSH terms

  • Amino Acid Chloromethyl Ketones / chemistry
  • Amino Acid Chloromethyl Ketones / pharmacology
  • Antigens, Neoplasm / chemistry*
  • Biomarkers, Tumor / antagonists & inhibitors*
  • Biomarkers, Tumor / chemistry*
  • Dipeptidyl Peptidase 4 / chemistry
  • Dipeptidyl Peptidase 4 / drug effects
  • Drug Design*
  • Gelatinases
  • Humans
  • Membrane Proteins
  • Models, Molecular
  • Oligopeptides / chemistry
  • Peptides / chemistry
  • Serine Endopeptidases / chemistry*
  • Serine Endopeptidases / drug effects*
  • Serine Proteinase Inhibitors / chemistry*
  • Serine Proteinase Inhibitors / pharmacology
  • Substrate Specificity
  • alpha-2-Antiplasmin / chemistry

Substances

  • Amino Acid Chloromethyl Ketones
  • Antigens, Neoplasm
  • Biomarkers, Tumor
  • Membrane Proteins
  • Oligopeptides
  • Peptides
  • Serine Proteinase Inhibitors
  • alpha-2-Antiplasmin
  • glycyl-glycyl-proline
  • Dipeptidyl Peptidase 4
  • Serine Endopeptidases
  • fibroblast activation protein alpha
  • Gelatinases