【摘要】 [目的]研究米曲霉酸性蛋白酶的纯化技术以及催化特性,为米曲霉酸性蛋白酶的开发和利用提供理论依据。[方法]采用丙酮沉淀,DEAE-Sephadex A-50柱层析方法分离纯化了米曲霉酸性蛋白酶,以酪蛋白为底物对其酶学性质进行了研究。[结果]结果表明:纯化倍数达到20.77;该酶最适pH值为6.0,最适温度为45℃;Fe2+、Mg2+对该蛋白酶的活性有明显的抑制作用,而Mn2+、Cu2+对该蛋白酶的活性有明显的激活作用。该蛋白酶Km=4.704 mg/ml,Vmax=22.27μg/min。[结论]米曲霉蛋白酶具有很好的应用前景。更多还原

【Abstract】 [Objective] The research aimed to study the acid proteinase in the Aspergillus oryzae in feedstuff,to provide the theoretical basis for the development and utilization of Aspergillus oryzae.[Method] The acid proteinase was purified from Aspergillus oryzae by acetone sedimentation,DEAE-Sephadex A-50 column chromatography.[Result] The results showed that the purification times was 20.77.The study on its catalyze character showed that the optimal pH value of the proteinase for casein was about 6.0,and the optimal temperature was about 45 ℃. The catalysis capability of the proteinase could be obviously activated by Mn2+ and Cu2+,but inhibited by Fe2+ and Mg2+.The Km of the proteinase was 4.704 mg/ml and the Vmax was 22.27 μg/min at the pH value 6.0 and temperature 45 ℃.[Conclusion] The proteinase purified from Aspergillus oryzae can be widely applied.更多还原