摘要
A colorimetric method has been established for a-glucosidase activity assay and its inhibitor screening. The method is based on the specific recognition between 1,4-phenylenediboronic acid （PDBA） and 4-aminophenyl-a-D-glucopyranoside （pAPG）, which may induce aggregation of pAPG-functionalized gold nano- particles （AuNPs） to achieve color change of the test solution. Because pAPG is the substrate of α-glucosidase, the aggregation of AuNPs will be influenced by α-glucosidase since there is no coordination reactivity between PDBA and 4-aminobenzene, the hydrolyzed product of pAPG catalyzed by the enzyme. Therefore, a simple and easily-operated colorimetric method for the assay of a-glucosidase activity can be developed. Under the optimized experimental conditions, the ratios of absorbance at a wavelength of 650 nm to that at 520 nm vary linearly with the α-glucosidase activity within a range from 0.05 to 1.1 U/mL with a lowest detection limit of 0.004 U/mL. Moreover, using the proposed method, the inhibition effect of gallic acid and quercetin on a-glucosidase activity can be tested with IC50 values of 1.16 mM and 1.82 μM, respectively. Thus, the method has a great potential not only for the detection of a-glucosidase activity, but also for the screening of its inhibitors.
一个比色的方法为屏蔽的 -glucosidase 活动试金和它的禁止者被建立了。方法基于在 1,4-phenylenediboronic 酸(PDBA ) 和 4-aminophenyl--d-glucopyranoside (pAPG ) 之间的特定的识别，它可以导致 pAPG-functionalized 金牌 nanoparticles (AuNPs ) 的聚集完成测试溶液的颜色变化。因为 pAPG 是 -glucosidase, 的底层，自从在 PDBA 和 4-aminobenzene 之间没有协作反应， AuNPs 的聚集将被 -glucosidase 影响， pAPG 的 hydrolyzed 产品由酶催化。因此，为 -glucosidase 活动的试金的一个简单、容易操作的比色的方法能被开发。在优化试验性的条件下面，在在 520 nm 的到那的 650 nm 的波长的吸收度的比率与 0.004 U/mL 的最低察觉限制从 0.05 ～ 1.1 U/mL 在一个范围以内与 -glucosidase 活动线性地变化。而且用建议方法，在 -glucosidase 活动的法国的酸和橡黄素的抑制效果能与 IC 被测试 < 潜水艇 class= “ a-plus-plus ” > 1.16 公里和 1.82 M 的 50 </sub> 价值分别地。因此，方法不仅为 -glucosidase 活动的察觉，而且为屏蔽它的禁止者有一个大潜力。
