Natural constituents of St. John's Wort inhibit the proteolytic activity of human thrombin
Natural constituents of St. John's Wort inhibit the proteolytic activity of human thrombin
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圣约翰草的天然成分抑制人凝血酶的蛋白水解活性
DOI：
10.1016/j.ijbiomac.2019.04.181
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发表时间：
2019
影响因子：
8.2
通讯作者：
Ge Guang-Bo
中科院分区：
文献类型：
--
作者：
Wei Ling-Hua;Chen Tian-Ran;Fang Hong-Bo;Jin Qiang;Zhang Shui-Jun;Hou Jie;Yu Yang;Dou Tong-Yi;Cao Yun-Feng;Guo Wen-Zhi;Ge Guang-Bo
凝血酶是一种多功能丝氨酸蛋白酶，负责可溶性纤维蛋白原的蛋白水解性降解，在凝血级联反应中起关键作用。目前，凝血酶抑制物治疗已被公认为预防和治疗血栓性疾病的有效治疗策略。在本研究中，天然成分的抑制作用。John‘s Wort通过基于荧光的生化分析仔细研究了抗人凝血酶。结果表明，大多数萘二蒽酮、黄酮类和双黄酮类化合物对人凝血酶有较强到中等程度的抑制作用。金丝桃素对凝血酶的抑制作用最强，IC50值为3.00 μM。进一步的抑制动力学研究表明，金丝桃素对凝血酶介导的醋酸Z-GRAMC水解酶具有明显的可逆抑制作用，抑制动力学的KI值为2.58 μM。抑制动力学分析表明，金丝桃素对凝血酶介导的醋酸Z-GRAMC水解酶具有混合抑制作用，这与金丝桃素既能与催化空腔结合又能与阴离子结合的胞外切点结合的结果一致。所有这些发现表明，金丝桃素是一种天然的凝血酶抑制剂，具有独特的二蒽酮骨架，可以作为开发性能更好的新型凝血酶抑制剂的候选药物。
Thrombin, a multifunctional serine protease responsible for the proteolytic hydrolysis of soluble fibrinogen, plays a pivotal role in the blood coagulation cascade. Currently, thrombin inhibitor therapy has been recognized as an effective therapeutic strategy for the prevention and treatment of thrombotic diseases. In this study, the inhibitory effects of natural constituents inSt. John's Wortagainst human thrombin are carefully investigated by a fluorescence-based biochemical assay. The results clearly demonstrate that most of naphthodianthrones, flavonoids and biflavones exhibit strong to moderate inhibition on human thrombin. Among all tested compounds, hypericin shows the most potent inhibitory capability against thrombin, with the IC50value of 3.00 μM. Further investigation on inhibition kinetics demonstrates that hypericin is a potent and reversible inhibitor against thrombin-mediated Z-GGRAMC acetate hydrolysis, with theKivalue of 2.58 μM. Inhibition kinetic analyses demonstrate that hypericin inhibits thrombin-mediated Z-GGRAMC acetate hydrolysis in a mixed manner, which agrees well with the results from docking simulations that hypericin can bind on both catalytic cavity and anion binding exosites. All these findings suggest that hypericin is a natural thrombin inhibitor with a unique dianthrone skeleton, which can be used as a good candidate to develop novel thrombin inhibitors with improved properties.