摘要
桔青霉(Penicillium citrinum)产核酸酶P1浓缩液采用活性炭脱色、硫酸铵分级沉淀、脱盐和凝胶层析等分离技术,得到核酸酶P1纯组分,并研究了该酶的酶学性质。该酶纯化后比酶活达到33967 U/mg,纯化倍数为8.48倍;该酶的米氏常数Km、最大反应速度Vm和催化常数Kcat分别为2.50 mmol/L、0.0864 mmol/(mL·min)和252.43 s-1。该酶最适温度为75℃,热稳定范围60~75℃;最适pH为5.5,pH稳定范围为4.0~6.0;Zn2+在1 mmol/L条件下对核酸酶P1有很好的激活作用,Cu2+和Co2+对该酶的抑制作用明显,而Ni2+、Fe2+、Mn2+等离子具有不同程度的抑制作用。本研究对于该酶的广泛应用奠定了科学基础。
The nuclease P1 was purified to obtain pure component by activated carbon decolorization,(NH4)2 SO4 precipitation, desalination and gel chromatography and its enzymatic properties was investigated. This purified enzyme had a specific activity of 33967 U/mg protein after 8.48-fold purification. The Michaelis constant(Km), the maximum reaction rates(Vm) and the catalytic constant(Kcat) of the purified enzyme were 2.50 mmol/L, 0.0864 mmol/(mL·min) and 252.43 s-1,respectively. The optimization pH and temperature for the nuclease P1 were at pH5.5 and 75 ℃. The enzyme was stable in the temperature range from 60 to 75 ℃ and in the pH range from 4.0 to 6.0. Zn2+ had a positive effect on the enzyme activity, while Cu2+ was a strong inhibitor of nuclease P1, Ni2+、Fe2+、Mn2+ had the different inhibition. This research laid a scientific foundation for the extensive application of the enzyme.
作者
李明
余华顺
喻晨
吴尧
龚大春
LI Ming;YU Huashun;YU Chen;WU Yao;GONG Dachun(Three Gorges University,Yichang 443002,China;China Key Laboratory of Light Industry Functional Yeast,China Three Gorges University,Yichang 443002,China;Angel Yeast Co.,Ltd,Special Enzyme Division,Yichang 443003,China)
出处
《食品工业科技》
CAS
北大核心
2021年第7期89-94,共6页
Science and Technology of Food Industry
基金
国家自然科学基金项目(21776162)
三峡大学学位论文培优基金项目资助(2019SSPY151)。
关键词
核酸酶P1
纯化
动力学参数
酶学性质
nuclease P1
purification
kinetic parameter
enzymatic property
