Human gelatinase/type IV procollagenase is a regular plasma component

Area of Science:

• Biochemistry
• Proteomics
• Enzymology

Background:

• Human plasma harbors multiple gelatinolytic proteases.
• Metalloproteases play significant roles in physiological and pathological processes.

Purpose of the Study:

• To characterize and identify gelatin-binding proteases in human plasma.
• To differentiate between plasma-derived and other gelatinase components.

Main Methods:

• Gelatin zymography to detect proteolytic activity.
• Affinity chromatography using gelatin-Sepharose for isolation.
• Immunoblotting for protein identification.
• Lectins (ConA, lentil) for further separation.

Main Results:

• A constant 66 kDa metalloprotease, identified as human fibroblast gelatinase/type IV procollagenase, was found.
• Additional proteases at 92, 130, and 225 kDa were identified as macrophage/granulocyte-derived.
• The 66 kDa protease could be separated from others using lectin affinity chromatography.
• The 66 kDa protease formed a disulfide-bonded dimer and a 62 kDa component upon isolation or storage.

Conclusions:

• Human plasma contains distinct gelatinase populations originating from fibroblasts and myeloid cells.
• The 66 kDa fibroblast gelatinase exhibits specific biochemical properties allowing its separation.
• Understanding these proteases is vital for their roles in extracellular matrix remodeling and disease.