Proline-Based Allosteric Inhibitors of Zika and Dengue Virus NS2B/NS3 Proteases

Abstract

The NS2B/NS3 serine proteases of the Zika and Dengue flaviviruses are attractive targets for the development of antiviral drugs. We report the synthesis and evaluation of a new, proline-based compound class that displays allosteric inhibition of both proteases. The structural features relevant for protease binding and inhibition were determined to establish them as new lead compounds for flaviviral inhibitors. Based on our structure–activity relationship studies, the molecules were further optimized, leading to inhibitors with submicromolar IC50 values and improved lipophilic ligand efficiency. The allosteric binding site in the proteases was probed using mutagenesis and covalent modification of the obtained cysteine mutants with maleimides, followed by computational elucidation of the possible binding modes. In infected cells, antiviral activity against Dengue virus serotype 2 using prodrugs of the inhibitors was observed. In summary, a novel inhibitor scaffold targeting an allosteric site shared between flaviviral NS2B/NS3 proteases is presented whose efficacy is demonstrated in vitro and in cellulo.

In vitro study of Hesperetin and Hesperidin as inhibitors of zika and chikungunya virus proteases

“…Using computational approaches, the localization of probable allosteric sites in ZIKV NS2B/NS3 pro and CHIKV nsP2 pro were defined previously [46,69,70]. They described that The residues involved in the interaction between protease and HST are labeled.…”

New Cysteine Protease Inhibitors: Electrophilic (Het)arenes and Unexpected Prodrug Identification for the Trypanosoma Protease Rhodesain

“…The highest inhibition of cathepsin L was found with the benzoic acid amide 4 (K i = 0.66 µM) and the amine 7 (K i = 1.6 µM). The latter also turned out to be the best inhibitor of cathepsin B and the Dengue virus (DENV) protease [47,48], however with lower inhibitory potency (Cath. B: K i = 4.4 µM; DENV PR: 31% at 20 µM).…”

Computer-Aided Design, Synthesis, and Antiviral Evaluation of Novel Acrylamides as Potential Inhibitors of E3-E2-E1 Glycoproteins Complex from Chikungunya Virus

“…In general, an adaptation of methods described by Tanja and collaborators (2019) was used [ 79 ]. Initially, aniline (1.0 eq.)…”

“…Moreover, 1 H NMR analysis showed that the chemical shifts (δ) for the hydroxyl (OH) from the carboxylic acid can appear between 12.38 and 12.71 ppm. Subsequently, the acrylamide derivatives (LQM328-337) were obtained by the TBTU-coupling reaction (Figure 3), using diisopropylethylamine (DIPEA) as a catalyst base [79], with yields from 52 to 92%. For all these final compounds, the purity degree was determined by the HPLC technique, which resulted in purities ranging from 95.3 to 99.9%, with retention time (R T ) between 3.07 and 3.88 min.…”