Structure-based identification of salicylic acid derivatives as malarial threonyl tRNA-synthetase inhibitors.

Emerging resistance to existing antimalarial drugs drives the search for new antimalarials, and protein translation is a promising pathway to target. Threonyl t-RNA synthetase (ThrRS) is one of the enzymes involved in this pathway, and it has been validated as an anti-malarial drug target. Here, we present 9 structurally diverse low micromolar Plasmodium falciparum ThrRS inhibitors that were identified using high-throughput virtual screening (HTVS) and were verified in a FRET enzymatic assay.

Discovery of Malarial Threonyl tRNA Synthetase Inhibitors by Screening of a Focused Fragment Library.

While threonyl tRNA synthetase (ThrRS) has clearly been validated as a prospective antimalarial drug target, the number of known inhbitors of this enzyme is still limited. In order to expand the chemotypes acting as inhibitors of ThrRS, a set of fragments were designed which incorporated bioisosteres of the -acylphosphate moiety of the aminoacyladenylate as an intermediate of an enzymatic reaction. -Acyl sulfamate- and -acyl benzenethiazolsulfonamide-based fragments and were identified as inhibitors of the ThrRSby biochemical assay at 100 μM concentration.

Exploring the Binding Pathway of Novel Nonpeptidomimetic Plasmepsin V Inhibitors.

Predicting the interaction modes and binding affinities of virtual compound libraries is of great interest in drug development. It reduces the cost and time of lead compound identification and selection. Here we apply path-based metadynamics simulations to characterize the binding of potential inhibitors to the aspartic protease plasmepsin V (plm V), a validated antimalarial drug target that has a highly mobile binding site.

3-(Adenosylthio)benzoic Acid Derivatives as SARS-CoV-2 Nsp14 Methyltransferase Inhibitors.

SARS-CoV-2 nsp14 guanine-7-methyltransferase plays an important role in the viral RNA translation process by catalyzing the transfer of a methyl group from -adenosyl-methionine (SAM) to viral mRNA cap. We report a structure-guided design and synthesis of 3-(adenosylthio)benzoic acid derivatives as nsp14 methyltransferase inhibitors resulting in compound with subnanomolar inhibitory activity and improved cell membrane permeability in comparison with the parent inhibitor. Compound acts as a bisubstrate inhibitor targeting both SAM and mRNA-binding pockets of nsp14.

Exploring Aspartic Protease Inhibitor Binding to Design Selective Antimalarials.

Selectivity is a major issue in the development of drugs targeting pathogen aspartic proteases. Here, we explore the selectivity-determining factors by studying specifically designed malaria aspartic protease (plasmepsin) open-flap inhibitors. Metadynamics simulations are used to uncover the complex binding/unbinding pathways of these inhibitors and describe the critical transition states in atomistic resolution.