Immobilization of Angiotensin Converting-enzyme on Chitosan Microspheres

Chitosan is a polysaccharide which is widely used in enzyme immobilization as a support. Angiotensin converting-enzyme (ACE) is an important member of the renin-angiotensin-aldosteronesystem which could cause high blood pressure. In this study, ACE was immobilized on chitosan microspheres with glutaraldehyde as cross-linking reagent. The optimum conditions and properties of Immobilization enzyme were investigated. The max ratio activity was 0.085 U/g under 2.5% glutaraldehyde and 8 mg/mL soluble enzyme for immobilized enzyme. The optimum pH, temperature and K-m of the immobilized enzyme were 7-9, 40-50 degrees C and 2.39 mmol/L. The immobilized ACE show higher thermal stability and can be used repeatedly to a certain extent. It was a fundamental study in order to develop the way of screening ACE inhibitor.