壳聚糖固定化血管紧张素转化酶及其性质

Immobilization of Angiotensin Converting-enzyme on Chitosan Microspheres

以壳聚糖微球为载体,戊二醛为交联剂固定化血管紧张素转化酶,研究了酶固定化的最优条件和固定化酶的性质.结果表明,在戊二醛质量分数为2.5%、给酶量为8mg/mL时,固定化酶的比活性最大,为0.085U/g.固定化酶在40～50℃,pH在7～9之间有最大活性,其米氏常数Km为2.39mmol/L.同时,固定化酶具有良好的稳定性,可重复利用.

Chitosan is a polysaccharide which is widely used in enzyme immobilization as a support. Angiotensin converting-enzyme（ACE） is an important member of the rennin-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,n of the immobilized enzyme were 7---9, 40--50℃ 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.