Isolation and characterization of plasminogen activators from hyperplastic and malignant prostate tissue

Area of Science:

• Biochemistry
• Molecular Biology
• Urology

Background:

• Prostate tissue contains various enzymes, including plasminogen activators, which play roles in physiological processes.
• Understanding the specific types and properties of these activators is crucial for elucidating prostate physiology and pathology.

Purpose of the Study:

• To purify and characterize plasminogen activators present in human prostate tissue.
• To compare the properties of purified prostate plasminogen activators with known urokinase and tissue-type plasminogen activators.

Main Methods:

• Purification involved reverse ammonium sulfate gradient solubilization, gelatin-Sepharose chromatography, Sephadex G-150 gel filtration, and Con A-Sepharose chromatography.
• Characterization included physicochemical, immunochemical, and functional analyses.
• Enzymatic activity was assessed using synthetic substrates and CNBr-fibrinogen fragments.

Main Results:

• Two distinct plasminogen activators were isolated from prostate tissue.
• The predominant activator (approximately 80%) was indistinguishable from high molecular weight urinary urokinase.
• A minor activator (approximately 20%) was immunochemically related to tissue-type plasminogen activator, with activity enhanced by fibrinogen fragments, but differed in molecular weight and substrate specificity from vascular plasminogen activator.

Conclusions:

• Prostate tissue expresses at least two distinct plasminogen activators.
• High molecular weight urokinase is the major form of plasminogen activator in the prostate.
• A distinct plasminogen activator, related to tissue-type plasminogen activator, is also present in the prostate.