山梨醇对黑曲霉源α-L-鼠李糖苷酶(r-Rha1)热稳定性的影响  

Effect of Sorbitol on Thermal Stability ofα-L-Rhamnosidase(r-Rha1)from Aspergillus niger

作　　者：叶家影 孙江 李文静[1] 倪辉[1,2,3] 李利君[1,2,3] 李清彪 YE Jiaying;SUN Jiang;LI Wenjing;NI Hui;LI Lijun;LI Qingbiao(College of Ocean Food and Biological Engineering,Jimei University,Xiamen 361021,China;Fujian Provincial Key Laboratory of Food Microbiology and Enzyme Engineering,Jimei University,Xiamen 361021,China;Research Center of Food Biotechnology of Xiamen City,Jimei University,Xiamen 361021,China)

机构地区：[1]集美大学海洋食品与生物工程学院,福建厦门361021 [2]集美大学福建省食品微生物与酶工程重点实验室,福建厦门361021 [3]集美大学厦门市食品生物工程技术研究中心,福建厦门361021

出　　处：《食品与生物技术学报》2022年第10期96-103,共8页Journal of Food Science and Biotechnology

基　　金：国家自然科学基金项目(U1805235);厦门市科技局项目(3502Z20203058);福建省平和县现代农业产业园中央财政奖补资金项目(PH2020)。

摘　　要：提高酶热稳定性是工业酶属性改造的重要目标。山梨醇作为广泛应用于提高酶稳定性的外源添加剂,目前对其影响酶热稳定性的机制仍不明确。因此,作者以黑曲霉源α-L-鼠李糖苷酶(r-Rha1)为研究对象,通过热失活动力学、圆二色谱和荧光光谱的谱学分析,研究山梨醇对α-L-鼠李糖苷酶热稳定性的影响机制。结果表明,在60~70℃下,加入山梨醇可改善α-L-鼠李糖苷酶的热稳定性;在60、65、70℃条件下,加入1.2 mol/L山梨醇可分别将半衰期提高29、25、10倍;圆二色谱和荧光光谱结果表明山梨醇通过增强α-L-鼠李糖苷酶的表面疏水活性和结构刚性,从而提高其热稳定性。通过探究山梨醇对α-L-鼠李糖苷酶热稳定性的影响,进一步证明山梨醇提高酶热稳定性的普遍适用性,同时为后续α-L-鼠李糖苷酶的工业应用提供了参考。The thermal stability of enzyme is an important target of industrial enzyme property modification.As an exogenous additive widely used to improve enzyme stability,the mechanism of sorbitol affecting enzyme thermal stability is still unclear.Therefore,the authors focused onα-L-rhamnosidase(r-Rha1)derived from Aspergillus niger and investigated the mechanism of sorbitol on the thermal stability ofα-L-rhamnosidase by thermal inactivation kinetics,circular dichroism and spectroscopic analysis of fluorescence mapping.Adding sorbitol improved the thermal stability ofα-L-rhamnosidase at 60~70℃,and 1.2 mol/L sorbitol increased the half-life ofα-L-rhamnosidase 29-fold,25-fold and 10-fold at 60,65℃and 70℃,respectively.The results of circular dichroism and fluorescence mapping plus indicated that sorbitol improved the thermal stability ofα-L-rhamnosidase by enhancing its surface hydrophobic activity and structural rigidity.The effect of sorbitol on the thermal stability ofα-L-rhamnosidase was investigated to further prove the general applicability of sorbitol in improving the thermal stability of the enzyme,while providing a reference for the subsequent industrial application ofα-L-rhamnosidase.

关 键 词：α-L-鼠李糖苷酶 山梨醇 热稳定性 荧光光谱 圆二色谱 

分 类 号：Q[生物学]