Division of Biological Chemistry and Drug Discovery, Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK.
Drug Discovery Unit, Wellcome Centre for Anti-Infectives Research, School of Life Sciences, University of Dundee, Dow Street, Dundee DD1 5EH, UK.
Cell Chem Biol. 2021 May 20;28(5):711-721.e8. doi: 10.1016/j.chembiol.2021.02.008. Epub 2021 Mar 9.
Phenotypic screening identified a benzothiophene compound with activity against Leishmania donovani, the causative agent of visceral leishmaniasis. Using multiple orthogonal approaches, oxidosqualene cyclase (OSC), a key enzyme of sterol biosynthesis, was identified as the target of this racemic compound and its enantiomers. Whole genome sequencing and screening of a genome-wide overexpression library confirmed that OSC gene amplification is associated with resistance to compound 1. Introduction of an ectopic copy of the OSC gene into wild-type cells reduced susceptibility to these compounds confirming the role of this enzyme in resistance. Biochemical analyses demonstrated the accumulation of the substrate of OSC and depletion of its product in compound (S)-1-treated-promastigotes and cell-free membrane preparations, respectively. Thermal proteome profiling confirmed that compound (S)-1 binds directly to OSC. Finally, modeling and docking studies identified key interactions between compound (S)-1 and the LdOSC active site. Strategies to improve the potency for this promising anti-leishmanial are proposed.
表型筛选鉴定出一种苯并噻吩类化合物，该化合物对引起内脏利什曼病的利什曼原虫具有活性。利用多种正交方法，发现角鲨烯环化酶（OSC），一种固醇生物合成的关键酶，是该外消旋化合物及其对映异构体的作用靶点。全基因组测序和全基因组过表达文库筛选证实，OSC 基因扩增与对化合物 1 的耐药性有关。将 OSC 基因的异位拷贝导入野生型细胞中，降低了对这些化合物的敏感性，证实了该酶在耐药性中的作用。生化分析表明，在化合物（S）-1 处理的前鞭毛体和无细胞膜制剂中，OSC 的底物积累，产物耗尽。热蛋白质组谱分析证实化合物（S）-1 直接与 OSC 结合。最后，建模和对接研究确定了化合物（S）-1 与 LdOSC 活性位点之间的关键相互作用。提出了提高这种有前途的抗利什曼原虫药物效力的策略。
