利用壳聚糖微球制备固定化乙酰胆碱酯酶

Preparation of the Immobilized Acetylcholinesterase Using Chitosan Microsphere as a Carrier

以壳聚糖微球（CS-MS）为载体,戊二醛（GA）为交联剂,制备固定化乙酰胆碱酯酶（AChE）。通过测定各种条件对酶活回收率影响,确定适宜的固定条件为：将1 g CS-MS用5 mL体积分数0.5%的GA活化0.25 h,然后加到含0.75 UAChE、pH 7.0~7.5的PBS中振荡反应24 h。所得到的酶活回收率可达81.94%,优于同类研究水平。红外光谱分析证实,AChE通过共价键和氢键结合到载体上。扫描电镜观察表明,经活化后CS-MS呈蜂窝状且表面平整光滑,利于酶的固定。因此,CS-MS是一种很有潜力的固定AChE载体。

Immobilized acetylcholinesterase（AChE） was prepared using chitosan microsphere （CS-MS） as a carrier and glutaraldehyde（GA） as a crosslinking agent.Effect of various immobilization conditions on the recovery of enzyme activity was investigated,the optimal immobilization process is as follows： 1 g of CS-MS activated by 5 mL of GA（0.5%） for 0.25 h is mixed with PBS（pH 7.0～pH 7.5） containing AChE of 0.75 U,then the mixture is agitated at 4 ℃ for 24 hours.Under these conditions,the immobilized AChE shows an improved activity recovery of 81.94% compared with other parallel investigations.Meanwhile,FT-IR analysis confirms that AChE is immobilized onto CS-MS successfully with covalent link and hydrogen bond.SEM examination reveals that CS-MS can offer excellent support for AChE immobilization due to its bee-liked structure and smooth surface.Therefore,CS-MS is a promising carrier suitable for AChE immobilization.