College of Food Science and Engineering, Qingdao Agricultural University, China.
Food Funct. 2018 Jan 24;9(1):355-363. doi: 10.1039/c7fo01381g.
Nanoparticles are novel and fascinating materials for tuning the activities of enzymes. In this study, we investigated the influence of spherical and polygonal starch nanoparticles (SNPs) on α-amylase activity and revealed the reaction mechanisms by ultraviolet-visible spectrophotometry, fluorescence spectroscopy, and circular dichroism (CD) spectroscopy. We discovered that both spherical and polygonal SNPs could inhibit the α-amylase activity, with half-inhibitory concentration values of 0.304 and 0.019 mg mL, respectively. Furthermore, spherical and polygonal SNPs followed competitive and mixed competitive inhibition mechanisms, respectively. The fluorescence data indicated that static quenching was dominant in the interaction between SNPs and α-amylase. The CD results demonstrated that the inhibition of α-amylase by SNPs was accompanied by the decreased intensity of the CD spectra of α-amylase. Our findings provide a novel strategy to inhibit α-amylase to reduce the digestion of starch, thus managing blood glucose levels.
纳米颗粒是一种新型且引人注目的材料，可用于调节酶的活性。在这项研究中，我们研究了球形和多边形淀粉纳米颗粒（SNPs）对α-淀粉酶活性的影响，并通过紫外-可见分光光度法、荧光光谱法和圆二色性（CD）光谱法揭示了反应机制。我们发现，球形和多边形 SNPs 均可抑制α-淀粉酶活性，其半抑制浓度值分别为 0.304 和 0.019mg/mL。此外，球形和多边形 SNPs 分别遵循竞争性和混合竞争性抑制机制。荧光数据表明，SNPs 与α-淀粉酶之间的相互作用以静态猝灭为主。CD 结果表明，SNPs 对α-淀粉酶的抑制伴随着α-淀粉酶 CD 光谱强度的降低。我们的研究结果为抑制α-淀粉酶以减少淀粉消化从而控制血糖水平提供了一种新策略。
