Related Experiment Videos
Purification of human protease nexin
The Journal of Biological Chemistry
|September 10, 1983
Summary
Protease nexin (PN) is a secreted factor that inhibits and facilitates the cellular degradation of proteases. A simple purification method yields milligram quantities of pure PN, retaining its biological functions.
Area of Science:
- Biochemistry
- Cell Biology
- Protease Inhibition
Background:
- Protease nexin (PN) forms stable complexes with serine proteases.
- PN mediates the binding, internalization, and degradation of these proteases by cells.
Purpose of the Study:
- To develop a simple procedure for purifying milligram quantities of PN.
- To characterize the purified PN and confirm its biological activities.
Main Methods:
- Culturing human foreskin cells on microcarriers with EGF and BSA.
- Ultrafiltration and heparin-Sepharose chromatography for initial purification.
- Octyl-agarose chromatography for further purification.
Main Results:
- A simple purification protocol yielded 60-90% recovery of PN with 90-97% purity.
- Purified PN has a molecular mass of ~51 kDa and exhibits protease inhibitory and cell-binding activities.
- PN forms SDS-stable complexes with thrombin, urokinase, and plasmin, and its activity is enhanced by heparin.
Conclusions:
- A straightforward method for obtaining highly pure protease nexin is established.
- Purified PN retains its functional properties, including protease inhibition and cellular complex formation.
- Proteolytic modification of PN occurs upon complex formation with thrombin.