Related Experiment Videos
Purification and characterization of platelet factor XI.
1Department of Medicine, University of Southern California, School of Medicine, Los Angeles 90033.
Thrombosis Research
|October 1, 1990
Summary
Platelet factor XI (Pt-XI), purified from human platelets, shares functional similarities with plasma factor XI. Both active site and adsorption functions reside on the same Mr = 44,500 chain in Pt-XI.
Area of Science:
- Biochemistry
- Hematology
- Molecular Biology
Background:
- Factor XI is a coagulation factor crucial for hemostasis.
- Understanding the structure and function of platelet-derived factor XI (Pt-XI) is important for hemostasis research.
Purpose of the Study:
- To purify and characterize human platelet factor XI (Pt-XI).
- To investigate the activation mechanism and functional domains of Pt-XI.
Main Methods:
- Purification of Pt-XI using affinity and ion-exchange chromatography.
- Analysis of Pt-XI structure and activation using SDS-PAGE, Western blotting, and radiolabeling with DFP.
- Functional assays including clotting activity and adsorption studies.
Main Results:
- Pt-XI was purified approximately 300-fold from human platelets.
- Native Pt-XI has a molecular weight of Mr = 245,000, dissociating into Mr = 52,000 subunits upon reduction.
- Activated Pt-XI exhibited coagulant activity, with the active site and adsorption domain localized to a Mr = 44,500 chain.
Conclusions:
- Platelet factor XI (Pt-XI) possesses distinct structural properties compared to plasma factor XI.
- In Pt-XI, the active site and adsorption functions are located on the same polypeptide chain (Mr = 44,500).
- This finding provides insights into the specific role of platelet factor XI in hemostasis.