| 摘要: |
| 【目的】 提高中性蛋白酶的固定化效果，对D101树脂固定中性蛋白酶的条件进行优化并对固定化酶的酶学性质进行研究。【方法】 以D101树脂吸附法固定中性蛋白酶，分别测定不同温度、时间和加酶量条件下固定化酶的固定化效果，并对固定化中性蛋白酶和游离中性蛋白酶的酶学性质进行比较研究。【结果】 D101树脂固定中性蛋白酶的最佳固定条件为：加酶量150 U/g，温度40 ℃，固定时间120 min，此时固定化酶的酶活回收率最高（70%）。固定化中性蛋白酶和游离中性蛋白酶的最适温度分别为46和40 ℃，最适pH值分别为7.4和7.2，表观米氏常数 Km分别为0.22 和0.20 mg/mL，最大酶促反应速度Vmax分别为0.39和0.21 mL/min。【结论】 以D101树脂固定中性蛋白酶后，固定化中性蛋白酶的活力、酶活回收率以及热稳定性和pH稳定性显著提高。 |
| 关键词: 中性蛋白酶 固定化酶 D101树脂 酪蛋白 游离酶 |
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| 基金项目:国家“863”高新技术研究与发展计划项目(2007AA10Z167)；国家“十一五”奶业重大科技支撑项目(2006BAD04A11) |
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| Study on immobilized condition optimization and properties of neutral proteinase with resin D101 |
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| Abstract: |
| 【Objective】 To improve the immobilization effect of neutral proteinase,the immobilization condition and enzyme properties of neutral proteinase were studied with resin D101. 【Method】 The absorption method was used to detect immobilization effect under different temperatures,pH and enzyme concentrations.The Km,thermal stability and pH stability of immobilized and soluble enzyme were studied.【Result】 The optimized results were achieved with 150 U/g of the amount of neutral proteinase to resin in weight,coupling temperature at 40 ℃ and immobilizing time of 120 min.The maximum yield of immobilized enzyme was 70%.The optimal temperature and optimal pH of immobilized and soluble enzyme were at 46 and 40 ℃,7.4 and 7.2,respectively.The Km and Vmax of immobilized and soluble enzyme were 0.22 mg/mL,0.39 mL/min and 0.20 mg/mL,0.21 mL/min,respectively. 【Conclusion】 Compared with free enzyme,the enzyme activity,enzyme recovery and stability of the immobilized enzyme were significantly increased. |
| Key words: neutral proteinase immobilized enzyme resin D101 casein soluble enzyme |
