Chen Guo-Ying, Zhang Hao, Yang Feng-Qing
School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 401331, China.
School of Chemistry and Chemical Engineering, Chongqing University, Chongqing, 401331, China.
Anal Chim Acta. 2021 Jan 15;1142:19-27. doi: 10.1016/j.aca.2020.10.047. Epub 2020 Oct 27.
In this study, a simple and portable enzyme activity assay and inhibitor screening method was developed based on β-Glucosidase-mediated cascade reaction in a personal glucose meter (PGM). The inhibition of castanospermine (β-Glucosidase inhibitor) on β-Glucosidase leads to reducing the yields of glucose and saligenin produced by the catalysis hydrolysis of D (-)-Salicin. The ferricyanide (K [Fe(CN)]) can be reduced by the products of glucose and saligenin to form ferrocyanide ([K[Fe(CN)]) in the glucose strips, and thereby get the electron to generate PGM detectable signals. This strategy can realize the direct determination of glucose and saligenin using PGM as simple as measuring the glucose in blood. Under the optimum experimental conditions, quantitative detection of β-Glucosidase in crude almond sample was achieved within the ranges of 1.0-9.0 U/mL with the limit of detection of 0.45 U/mL. The recoveries of β-Glucosidase spiked with two different concentrations (3.0 and 6.0 U/mL) in the crude bitter almond extracts were determined as 96.2% and 84.3%, respectively. Furthermore, gallic acid, protocatechualdehyde, cryptochlorogenic acid, epigallocatechin, epicatechin and vanillic acid exhibited good inhibitory effect (all higher than 40%) on β-Glucosidase. In addition, tea polyphenol extracts of raw Pu-erh and Fuding white tea had good inhibition potency and the % of inhibition were (29.0 ± 3.5)% and (21.1 ± 2.2)% on β-Glucosidase, respectively. Finally, molecular docking study indicated that hydrogen bonding plays an important role in the interaction between the compounds and β-Glucosidase. The enzyme activity assay and inhibitor screening method developed in present study using PGM based on β-Glucosidase-mediated cascade reaction would be of value for expanding the application of PGM in non-glucose target analysis.
在本研究中，基于个人血糖仪（PGM）中β-葡萄糖苷酶介导的级联反应，开发了一种简单便携的酶活性测定和抑制剂筛选方法。栗精胺（β-葡萄糖苷酶抑制剂）对β-葡萄糖苷酶的抑制作用导致D（-）-水杨苷催化水解产生的葡萄糖和水杨醇产量降低。葡萄糖和水杨醇的产物可将铁氰化物（K[Fe(CN)]）还原为亚铁氰化物（[K[Fe(CN)]），从而在葡萄糖试条中获得电子以产生PGM可检测信号。该策略能够像检测血液中的葡萄糖一样简单地使用PGM直接测定葡萄糖和水杨醇。在最佳实验条件下，粗杏仁样品中β-葡萄糖苷酶的定量检测范围为1.0 - 9.0 U/mL，检测限为0.45 U/mL。在苦杏仁粗提物中添加两种不同浓度（3.0和6.0 U/mL）的β-葡萄糖苷酶，回收率分别为96.2%和84.3%。此外，没食子酸、原儿茶醛、隐绿原酸、表没食子儿茶素、表儿茶素和香草酸对β-葡萄糖苷酶表现出良好的抑制作用（均高于40%）。另外，生普洱茶和福鼎白茶的茶多酚提取物对β-葡萄糖苷酶具有良好的抑制效力，抑制率分别为（29.0 ± 3.5）%和（21.1 ± 2.2）%。最后，分子对接研究表明氢键在化合物与β-葡萄糖苷酶的相互作用中起重要作用。本研究基于β-葡萄糖苷酶介导的级联反应利用PGM开发的酶活性测定和抑制剂筛选方法，对于拓展PGM在非葡萄糖目标分析中的应用具有重要价值。
