Human cationic trypsinogen. Purification, characterization, and characteristics of autoactivation

Area of Science:

• Biochemistry
• Proteomics
• Enzymology

Background:

• Human pancreatic cationic trypsinogen is a key digestive enzyme precursor.
• Understanding its activation mechanism is crucial for physiological and pathological studies.

Purpose of the Study:

• To purify human pancreatic cationic trypsinogen to homogeneity.
• To investigate the autoactivation kinetics of purified human trypsinogen.
• To compare human trypsinogen autoactivation with that of bovine trypsinogen.

Main Methods:

• Purification using ion exchange chromatography (Sulfopropyl Sephadex) and affinity chromatography (lima bean trypsin inhibitor-agarose).
• Homogeneity assessment via polyacrylamide gel electrophoresis (PAGE) at various pH and SDS-PAGE.
• Autoactivation studies at pH 5.6 and 8.0, with varying calcium (Ca2+) concentrations.

Main Results:

• Human pancreatic cationic trypsinogen was successfully purified to homogeneity.
• Autoactivation of human trypsinogen is rapid at pH 5.6, with optimal rate at approximately 1 mM Ca2+.
• This activation rate and calcium dependency contrasts sharply with bovine trypsinogen.

Conclusions:

• Human trypsinogen exhibits distinct autoactivation properties compared to bovine trypsinogen.
• The rapid autoactivation at physiological pH and low calcium has significant implications for pancreatic physiology.
• Further research into the differential activation mechanisms is warranted.