a Shenzhen Key Laboratory of Marine Bioresources and Ecology/Shenzhen Key Laboratory of Microbial Genetic Engineering, College of Life Sciences and Oceanography , Shenzhen University , Shenzhen , China.
b Key Laboratory of Optoelectronic Devices and Systems of Ministry of Education and Guangdong Province, College of Optoelectronic Engineering , Shenzhen University , Shenzhen , China.
J Biomol Struct Dyn. 2019 Aug;37(13):3379-3387. doi: 10.1080/07391102.2018.1515115. Epub 2018 Nov 17.
It is well known that Ligupurpuroside B is a water-soluble polyphenolic compound and used to brew bitter tea with antioxidant activities. It acted as a stimulant to the central nervous system and a diuretic (increase the excretion of urine), was used to treat painful throat and high blood pressure, and also exerted weight-loss function. In this regard, a detailed investigation on the mechanism of interaction between Ligupurpuroside B and trypsin could be of great interest to know the pharmacokinetic behavior of Ligupurpuroside B and for the design of new analogues with effective pharmacological properties. Ligupurpuroside B successfully quenched the intrinsic fluorescence of trypsin via static quenching mechanism. The binding constants () at three temperatures (288, 298, and 308 K) were 1.7841 × 10, 1.6251 × 10 and 1.5483 × 10 L mol, respectively. Binding constants revealed the stronger binding interaction between Ligupurpuroside B and trypsin. The number of binding sites approximated to one, indicating a single class of binding for Ligupurpuroside B in trypsin. The enzyme activity result suggested that Ligupurpuroside B can inhibit trypsin activity. Thermodynamic results revealed that both hydrogen bonds and hydrophobic interactions play main roles in stabilization of Ligupurpuroside B-trypsin complex. Circular dichroism (CD) results showed that the conformation of trypsin changed after bound to ligupurpuroside B. Molecular docking indicated that Ligupurpuroside B can enter the hydrophobic cavity of trypsin and was located near Trp215 and Tyr228 of trypsin. Communicated by Ramaswamy H. Sarma.
众所周知，滇紫草素 B 是一种水溶性多酚化合物，用于酿造具有抗氧化活性的苦茶。它作为中枢神经系统的兴奋剂和利尿剂（增加尿液排泄），用于治疗喉咙疼痛和高血压，并具有减肥功能。在这方面，详细研究滇紫草素 B 与胰蛋白酶之间的相互作用机制，可以了解滇紫草素 B 的药代动力学行为，并设计具有有效药理性质的新类似物。滇紫草素 B 通过静态猝灭机制成功猝灭胰蛋白酶的内源性荧光。在三个温度（288、298 和 308 K）下的结合常数（）分别为 1.7841×10、1.6251×10 和 1.5483×10 L mol。结合常数表明滇紫草素 B 与胰蛋白酶之间存在更强的结合相互作用。结合位点数接近 1，表明滇紫草素 B 在胰蛋白酶中存在单一结合类。酶活性结果表明滇紫草素 B 可以抑制胰蛋白酶活性。热力学结果表明，氢键和疏水相互作用都在稳定滇紫草素 B-胰蛋白酶复合物中起主要作用。圆二色性（CD）结果表明，胰蛋白酶的构象在与滇紫草素 B 结合后发生变化。分子对接表明，滇紫草素 B 可以进入胰蛋白酶的疏水腔，并位于胰蛋白酶的 Trp215 和 Tyr228 附近。由 Ramaswamy H. Sarma 传达。
