Fragment-Based Drug Discovery for Trypanosoma brucei Glycosylphosphatidylinositol-Specific Phospholipase C through Biochemical and WaterLOGSY-NMR Methods. (22nd February 2022)

• Record Type: Journal Article
• Authors: Ibrahim, Mohammed Auwal; Yamasaki, Tomoko; Furukawa, Koji; Yamasaki, Kazuhiko
• Is Part Of: Journal of biochemistry. Volume 171:Number 6(2022)
• Page Start: 619
• Page End: 629
• Publication Date: 2022-02-22
• Subjects: antigenic variation -- catalytic pocket -- docking simulation -- enzyme inhibition -- GPI anchor; Biochemistry -- Periodicals; Biochemistry -- Periodicals; Electronic journals; 572.05
• DOI: 10.1093/jb/mvac020
• Languages: English
• ISSNs: 0021-924X

Abstract

Abstract: Glycosylphosphatidylinositol-specific phospholipase C (GPI-PLC) of Trypanosoma brucei, the causative protozoan parasite of African trypanosomiasis, is a membrane-bound enzyme essential for antigenic variation, because it catalyses the release of the membrane-bound form of variable surface glycoproteins. Here, we performed a fragment-based drug discovery of Tb GPI-PLC inhibitors using a combination of enzymatic inhibition assay and water ligand observed via gradient spectroscopy (WaterLOGSY) NMR experiment. The Tb GPI-PLC was cloned and overexpressed using an Escherichia coli expression system followed by purification using three-phase partitioning and gel filtration. Subsequently, the inhibitory activity of 873 fragment compounds against the recombinant Tb GPI-PLC led to the identification of 66 primary hits. These primary hits were subjected to the WaterLOGSY NMR experiment where 10 fragment hits were confirmed to directly bind to the Tb GPI-PLC. These included benzothiazole, chlorobenzene, imidazole, indole, pyrazol and quinolinone derivatives. Molecular docking simulation indicated that six of them share a common binding site, which corresponds to the catalytic pocket. The present study identified chemically diverse fragment hits that could directly bind and inhibit the Tb GPI-PLC activity, which constructed a framework for fragment optimization or linking towards the design of novel drugs for African trypanosomiasis. Graphical Abstract: