RESUMO
Ribosomal protein S1 (RpsA) has been identified as a novel target of pyrazinoic acid (POA), which is the active form of pyrazinamide (PZA), in vivo. RpsA plays a crucial role in trans-translation, which is widespread in microbes. In our investigation, we first described the discovery of promising RpsA antagonists for drug-resistant mycobacterium (MtRpsAd438A) and M. smegmatis, as well as wild-type M. tuberculosis. These antagonists were discovered via structure/ligand-based virtual screening approaches. A total of 21 targeted compounds were selected by virtual screening, combined scores, affinity, similarities and rules for potential as drugs. Next, the affinities of these compounds for three targeted proteins were tested in vitro by applying various technologies, including fluorescence quenching titration (FQT), saturation transfer difference (STD), and chemical shift perturbation (CSP) assays. The results showed that seven compounds had a high affinity for the targeted proteins. Our discovery set the stage for discovering new chemical entities (NCEs) for PZA-resistant tuberculosis and providing key residues for rational drug design to target RpsA.
Assuntos
Antituberculosos/farmacologia , Azóis/farmacologia , Proteínas de Bactérias/antagonistas & inibidores , Compostos Heterocíclicos com 2 Anéis/farmacologia , Proteínas Ribossômicas/antagonistas & inibidores , Antituberculosos/química , Azóis/química , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Sítios de Ligação , Avaliação Pré-Clínica de Medicamentos , Compostos Heterocíclicos com 2 Anéis/química , Testes de Sensibilidade Microbiana , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Mutação , Mycobacterium smegmatis/efeitos dos fármacos , Mycobacterium tuberculosis/efeitos dos fármacos , Proteínas Ribossômicas/química , Proteínas Ribossômicas/genética , SoftwareRESUMO
Oxidative damage to the constituents of the eye lens is a major mechanism in the initiation and development of cataract. Lunasin, a 43-amino acids chemoprevention peptide, has been proved to possess potent anti-oxidative activity other than its established anticancer activities. Herein, we explored whether lunasin has preventative effects on d-galactose-induced experimental cataract in rat. After modeling, SD rats were administrated by instillation, 80 µM of lunasin eye drops to each eye thrice daily and consecutively for 30 days. As a result, lunasin treatment effectively inhibited the progression of d-galactose-induced experimental cataract, and protected the lenses of rats from oxidative damage and attenuated the lipid peroxidation through up-regulation of antioxidant enzymes, and inhibited the activation of polyol pathway by decreasing AR activity. Additionally, in vitro studies proved that lunasin treatment could protect human lens epithelial cells (hLECs) against d-galactose induced cell damage and apoptosis, and up-regulate antioxidant enzymes. This is the first demonstration that lunasin could inhibit d-galactose-induced experimental cataract in rats by protecting against oxidative damage and inhibiting the activation of polyol pathway.