金属离子对米糠解脂酶活性影响的研究

实验用CaCl2溶液从脱脂米糠中提取解脂酶,经(NH4)2SO4沉淀后,获得粗酶。用分光光度法测定了6种不同的金属离子对酶活力的影响,实验结果表明,在浓度为0.01mol/L时,Zn2+、Fe2+、Mg2+等金属离子对米糠解脂酶起激活作用,Ca2+、Ba2+、Cu2+等离子对酶活性起抑制作用。当离子浓度在0.001mol/L到0.1mol/L之间变化时,随着离子浓度的增加,Ca2+、Ba2+、Cu2+3种金属离子会使酶的活性逐渐降低;而Zn2+、Fe2+、Mg2+3种金属离子浓度在0.001～0.02mol/L的变化范围内,酶活性随着离子浓度的升高而逐渐升高,在0.02～0.1mol/L的变化范围内,酶活性随着离子浓度的升高而逐渐降低。

Study on the influence of metal ions to activity of rice bran lipase

The lipase extracted from defatted rice bran with calaium chloride.We got crude lipase by precipitation with ammonium sulfate.We determined its activity by colorimetry under the presence of one of the six kinds of metal ions.Experimental data showed when the concentration of metal ion was at 0.01mol/L,Zn2+,Fe2+ and Mg2+ enhanced its activity,while Ca2+,Ba2+ and Cu2+ bated its activity.When the concentration of metal ion changed between 0.001mol/L and 0.1mol/L,Ca2+,Ba2+ and Cu2+ decreased its activity with the increase of concentration of metal ion;while Zn2+,Fe2+ and Mg2+ increased its activity when the concentration of metal ion changed from 0.001mol/L and 0.02mol/L and decrease its activity when the concentration changed between 0.02mol/L and 0.1mol/L.