The preparation and properties of bovine enterokinase

Area of Science:

• Biochemistry
• Enzymology
• Proteomics

Background:

• Enterokinase is a key enzyme in the digestive system.
• Understanding its properties is crucial for digestive physiology research.

Purpose of the Study:

• To purify and characterize bovine enterokinase from duodenal mucosa.
• To compare its properties with enterokinase from other sources.

Main Methods:

• Enzyme purification using deoxycholate extraction, ammonium sulfate fractionation, DEAE-cellulose chromatography, and affinity chromatography.
• Characterization of enzyme properties including molecular weight, subunit composition, substrate hydrolysis, and inhibition kinetics.

Main Results:

• Purified bovine enterokinase has a molecular weight of 150,000 Da, composed of heavy (115,000 Da) and light (35,000 Da) chains.
• The enzyme exhibits substrate specificity for lysine and arginine residues and activates bovine trypsinogen.
• Its amino acid composition and subunit sizes differ from duodenal content enterokinase but resemble porcine enterokinase.

Conclusions:

• Bovine duodenal mucosal enterokinase possesses unique biochemical and structural features.
• These characteristics distinguish it from enterokinase isolated from duodenal contents.
• The enzyme's properties show similarities to porcine enterokinase, suggesting conserved features across species.