International Cooperation Base of Pesticide and Green Synthesis (Hubei), Key Laboratory of Pesticide & Chemical Biology (CCNU), Ministry of Education, Department of Chemistry, Central China Normal University, Wuhan, 430079, China.
International Cooperation Base of Pesticide and Green Synthesis (Hubei), Key Laboratory of Pesticide & Chemical Biology (CCNU), Ministry of Education, Department of Chemistry, Central China Normal University, Wuhan, 430079, China; School of Chemistry and Chemical Engineering, Anhui University of Technology, Maanshan, 243002, China.
Eur J Med Chem. 2019 Dec 15;184:111749. doi: 10.1016/j.ejmech.2019.111749. Epub 2019 Sep 30.
Fructose-1,6-bisphosphatase (FBPase) is an essential enzyme of GNG pathway. Significant advances demonstrate the FBPase plays a critical role in treatment of diabetes. Numerous FBPase inhibitors were developed by targeting AMP site, nevertheless, none of these inhibitors has exhibited suitable potency and druggability. Herein, a new allosteric site (C128) on FBPase was discovered, and several nitrostyrene compounds exhibiting potent FBPase inhibitions were found covalently bind to C128 site on FBPase. Mutagenesis suggest that C128 is the only cysteine that can influence FBPase inhibition, the N125-S124-S123 pathway was most likely involved in allosteric signaling transmission between C128 and active site. However, these nitrostyrenes may bind with multiple cysteine besides C128 in FBPase. To improve pocket selectivity, a series of novel compounds (14a-14n) were re-designed rationally by integrating fragment-based covalent virtual screening and machine-learning-based synthetic complexity evaluation. As expected, the mass spectrometry validated that the proportion of title compounds binding to the C128 in FBPase was significantly higher than that of nitrostyrenes. Notably, under physiological and pathological conditions, the treatment of compounds 14b, 14c, 14i or 14n led to potent inhibition of glucose production, as well as decreased triglyceride and total cholesterol levels in mouse primary hepatocytes. We highlight a novel paradigm that molecular targeting C128 site on FBPase can have potent hypoglycemic effect.
果糖-1,6-二磷酸酶 (FBPase) 是 GNG 途径的一种必需酶。大量研究进展表明，FBPase 在糖尿病治疗中起着关键作用。已有许多针对 AMP 结合位点的 FBPase 抑制剂被开发出来，但这些抑制剂都没有表现出适当的效力和可药性。在此，我们发现了 FBPase 上的一个新的别构位点 (C128)，并发现了几种表现出强效 FBPase 抑制作用的硝呋烯化合物与 FBPase 上的 C128 位点共价结合。突变分析表明，C128 是唯一可以影响 FBPase 抑制的半胱氨酸，N125-S124-S123 途径很可能参与了 C128 和活性位点之间的别构信号传递。然而，这些硝呋烯化合物可能除了与 FBPase 上的 C128 结合外，还与多个半胱氨酸结合。为了提高口袋选择性，我们通过整合基于片段的共价虚拟筛选和基于机器学习的合成复杂度评估，对一系列新型化合物（14a-14n）进行了合理设计。不出所料，质谱验证了标题化合物与 FBPase 中 C128 结合的比例明显高于硝呋烯化合物。值得注意的是，在生理和病理条件下，化合物 14b、14c、14i 或 14n 的治疗导致葡萄糖生成的强烈抑制，以及小鼠原代肝细胞中甘油三酯和总胆固醇水平的降低。我们强调了一种新的范式，即靶向 FBPase 上的 C128 位点可以产生有效的降血糖作用。
