A study of tissue plasminogen activator forms from human small intestine

Area of Science:

• Biochemistry
• Molecular Biology
• Gastroenterology

Background:

• Tissue plasminogen activator (tPA) is crucial for fibrinolysis.
• The presence and forms of tPA in the human small intestine are not well-characterized.

Purpose of the Study:

• To investigate the forms of plasminogen activators in human small intestine homogenates.
• To characterize the nature of tPA-like activities found in this tissue.

Main Methods:

• Human small intestine homogenates were analyzed.
• Gel filtration chromatography (Sephadex G-200) was used to assess molecular size.
• Immunological cross-reactivity with anti-tPA antiserum was performed.
• Solubility and dissociation studies using NaCl, Triton X-100, potassium thiocyanate, and guanidine-HCl were conducted.

Main Results:

• Two distinct plasminogen activator activities cross-reacting with anti-tPA antiserum were detected.
• One activity exhibited slow mobility, suggesting a degraded form of tPA.
• The second activity showed rapid migration and dispersion, indicative of tPA aggregates.
• These aggregates resisted dissociation by mild agents but were separated from tPA by 4 M guanidine-HCl.

Conclusions:

• Human small intestine contains at least two forms of tPA-like molecules.
• These forms include a potentially degraded tPA and aggregates of tPA with other components.
• Guanidine-hydrochloride is effective in dissociating tPA aggregates found in intestinal tissue.