Physical Sciences and Mathematics Commons^™

Examining The Substrate Specificity Of Factor Xiiia Towards Peptide Substrate Modelsac Fibrin Domains., Jacob Bell

College of Arts & Sciences Senior Honors Theses

In the blood coagulation cascade, Factor XIII (FXIII) is a zymogen that is activated by thrombin (IIa) and Ca2+. Activated FXIII (FXIIIa) functions as a transglutaminase in the final steps of the clotting cascade by forming covalent crosslinks between fibrin monomers at reactive glutamine residues. This forms a stable clot structure, secure from proteolytic degradation. To monitor FXIIIa substrate sequence specificity, the glutamine-containing peptide models S. aureus Fnb A (100-114), α2AP(Q4P) (1-15) and K9 (1-10) were introduced to the enzyme in the presence of 15NH4Cl. Using MALDI-TOF MS and 15N HSQC NMR experiments, it was seen that α2AP(Q4P) (1-15) and …