RT Journal Article
SR Electronic
T1 Identification of a phage display-derived peptide interacting with the N-terminal region of Factor VII activating protease (FSAP) enables characterization of zymogen activation
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2022.01.09.475526
DO 10.1101/2022.01.09.475526
A1 Seidl, Sebastian
A1 Nielsen, Nis Valentin
A1 Escheid, Michael
A1 Haug, Bengt Erik
A1 Stensland, Maria
A1 Thiede, Bernd
A1 Declerck, Paul J.
A1 Åge Løset, Geir
A1 Kanse, Sandip M.
YR 2022
UL http://biorxiv.org/content/early/2022/01/09/2022.01.09.475526.abstract
AB Increased Factor VII activating protease (FSAP) activity has a protective effect in diverse disease conditions as inferred from studies in FSAP−/− mice and humans deficient in FSAP activity due to a single nucleotide polymorphism. The activation of FSAP zymogen in plasma is mediated by extracellular histones that are released during tissue injury or inflammation or by positively charged surfaces. However, it is not clear if this activation mechanism is specific and amenable to manipulation. Using a phage display approach we have identified a peptide, NNKC9/41, that activates pro-FSAP in plasma. Other commonly found zymogens in the plasma were not activated. Binding studies with FSAP domain deletion mutants indicate that the N-terminus of FSAP is the key interaction site of this peptide. Blocking the contact pathway of coagulation did not influence pro-FSAP activation by the peptide. In a monoclonal antibody screen, we identified MA-FSAP-38C7 that prevented the activation of pro-FSAP by the peptide. This antibody bound to the LESLDP sequence (amino acids 30-35) in the N-terminus of FSAP. The plasma clotting time was shortened by NNKC9/41 and this was reversed by MA-FSAP-38C7 demonstrating the utility of this peptide. Identification of this peptide, and the corresponding interaction site, provides proof of principle that it is possible to activate a single protease zymogen in blood in a specific manner. Peptide NNKC/41 will be useful as a tool to delineate the molecular mechanism of activation of pro-FSAP in more detail, elucidate its biological role.Competing Interest StatementThe authors have declared no competing interest.