Development of disulfide-derived fructose-1,6-bisphosphatase (FBPase) covalent inhibitors for the treatment of type 2 diabetes.

Fructose-1,6-bisphosphatase (FBPase), as a key rate-limiting enzyme in the gluconeogenesis (GNG) pathway, represents a practical therapeutic strategy for type 2 diabetes (T2D). Our previous work first identified cysteine residue 128 (C128) was an important allosteric site in the structure of FBPase, while pharmacologically targeting C128 attenuated the catalytic ability of FBPase. Herein, ten approved cysteine covalent drugs were selected for exploring FBPase inhibitory activities, and the alcohol deterrent disulfiram displayed superior inhibitory efficacy among those drugs. Based on the structure of lead compound disulfiram, 58 disulfide-derived compounds were designed and synthesized for investigating FBPase inhibitory activities. Optimal compound 3a exhibited significant FBPase inhibition and glucose-lowering efficacy in vitro and in vivo. Furthermore, 3a covalently modified the C128 site, and then regulated the N125-S124-S123 allosteric pathway of FBPase in mechanism. In summary, 3a has the potential to be a novel FBPase inhibitor for T2D therapy.

The discovery of potential phosphopantetheinyl transferase Ppt2 inhibitors against drug-resistant Candida albicans.

With the high-frequency use or abuse of antifungal drugs, the crisis of drug-resistant fungi continues to increase worldwide; in particular, the infection of drug-resistant Candida albicans brings the great challenge to the clinical treatment. Therefore, to decelerate the spread of this resistance, it is extremely urgent to facilitate the new antifungal targets with novel drugs. Phosphopantetheinyl transferases PPTases (Ppt2 in Candida albicans) had been identified in bacterium and fungi and mammals, effects as a vital enzyme in the metabolism of organisms in C. albicans. Ppt2 transfers the phosphopantetheinyl group of coenzyme A to the acyl carrier protein Acp1 in mitochondria for the synthesis of lipoic acid that is essential for fungal respiration, so making Ppt2 an ideal target for antifungal drugs. In this study, 110 FDA-approved drugs were utilized to investigate the Ppt2 inhibition against drug-resistant Candida albicans by the improved fluorescence polarization experiments, which have enough druggability and structural variety under the novel strategy of drug repurposing. Thereinto, eight agents revealed the favourable Ppt2 inhibitory activities. Further, broth microdilution assay of incubating C. albicans with these eight drugs showed that pterostilbene, procyanidine, dichlorophen and tea polyphenol had the superior MIC values. In summary, these findings provide more valuable insight into the treatment of drug-resistant C. albicans.