【摘要】 目的探讨以甲壳胺为载体固定乙酰胆碱酯酶的最佳条件及固定化酶的理化性质。方法以戊二醛为交联剂,将乙酰胆碱酯酶固定在甲壳胺上,并分别测定固定化酶与溶液酶的活力。结果固定化酶与溶液酶的最适温度相同,均为37℃;固定化酶与溶液酶最适pH分别为8.2、8.0;固定化酶在50℃仍有较高热稳定性,而溶液酶活力明显下降;固定化酶的米氏常数Km=0.84 mmol/L,溶液酶的Km=1.16 mmol/L;固定化酶活力回收为44.66%,在重复使用8次后仍能保持原有活力的50%。结论该固定化酶与溶液酶相比,其热稳定性提高,与底物的亲和能力增大,且重复使用性较好。更多还原

【Abstract】 Objective To investigate the optimum condition and properties of immobilization of acetylcholinesterase with chitosan as its carrier.Methods Acetylcholinesterase was immobilized on chitosan by using glutaraldehyde as cross-linking reagent.The activities of immobilized enzyme and soluble enzyme were respectively determined.Results The optimum pH,temperature,Km of the immobilized enzyme were 8.2,37 ℃,0.84 mmol/L,respectively,and those of soluble enzyme were 8.0,37 ℃,1.16 mmol/L,respectively.The activity retention of immobilized enzyme was approximately 44.66%.The bound enzyme retained approximately 50% of its initial activity after 8 cycles of use.Conclusion The immobilized enzyme showed higher thermal stability and affinity to substrate than the soluble enzyme,and to a certain extent can be used repeatedly.更多还原