A probable means to an end: exploring P131 pharmacophoric scaffold to identify potential inhibitors of Cryptosporidium parvum inosine monophosphate dehydrogenase

Exploring the Effects of Chirality of 5-methyl-5-[4-(4-oxo-3H-quinazolin-2- yl)phenyl]imidazolidine-2,4-dione and its Derivatives on the Oncological Target Tankyrase 2. Atomistic Insights

BACKGROUND

Tankyrases (TNKS) are homomultimers existing in two forms, viz. TNKS1 and TNKS2. TNKS2 plays a pivotal role in carcinogenesis by activating the Wnt//β- catenin pathway. TNKS2 has been identified as a suitable target in oncology due to its crucial role in mediating tumour progression. The discovery of 5-methyl-5-[4-(4-oxo-3H-quinazolin-2-yl) phenyl]imidazolidine-2,4-dione, a hydantoin phenylquinazolinone derivative which exists as a racemic mixture and in its pure enantiomer forms, has reportedly exhibited inhibitory potency towards TNKS2. However, the molecular events surrounding its chirality towards TNKS2 remain unresolved.

METHODS

Herein, we employed in silico methods such as molecular dynamics simulation coupled with binding free energy estimations to explore the mechanistic activity of the racemic inhibitor and its enantiomer forms on TNKS2 at a molecular level.

RESULTS

Favourable binding free energies were noted for all three ligands propelled by electrostatic and van der Waals forces. The positive enantiomer demonstrated the highest total binding free energy (-38.15 kcal/mol), exhibiting a more potent binding affinity to TNKS2. Amino acids PHE1035, ALA1038, and HIS1048; PHE1035, HIS1048 and ILE1039; and TYR1060, SER1033 and ILE1059 were identified as key drivers of TNKS2 inhibition for all three inhibitors, characterized by the contribution of highest residual energies and the formation of crucial high-affinity interactions with the bound inhibitors. Further assessment of chirality by the inhibitors revealed a stabilizing effect of the complex systems of all three inhibitors on the TNKS2 structure. Concerning flexibility and mobility, the racemic inhibitor and negative enantiomer revealed a more rigid structure when bound to TNKS2, which could potentiate biological activity interference. The positive enantiomer, however, displayed much more elasticity and flexibility when bound to TNKS2.

CONCLUSION

Overall, 5-methyl-5-[4-(4-oxo-3H-quinazolin-2-yl)phenyl]imidazolidine-2,4-dione and its derivatives showed their inhibitory prowess when bound to the TNKS2 target via in silico assessment. Thus, results from this study offer insight into chirality and the possibility of adjustments of the enantiomer ratio to promote greater inhibitory results. These results could also offer insight into lead optimization to enhance inhibitory effects.

Treating cryptosporidiosis: A review on drug discovery strategies

Despite several decades of research on therapeutics, cryptosporidiosis remains a major concern for human and animal health. Even though this field of research to assess antiparasitic drug activity is highly active and competitive, only one molecule is authorized to be used in humans. However, this molecule was not efficacious in immunocompromised people and the lack of animal therapeutics remains a cause of concern. Indeed, the therapeutic arsenal needs to be developed for both humans and animals. Our work aims to clarify research strategies that historically were diffuse and poorly directed. This paper reviews in vitro and in vivo methodologies to assess the activity of future therapeutic compounds by screening drug libraries or through drug repurposing. It focuses on High Throughput Screening methodologies (HTS) and discusses the lack of knowledge of target mechanisms. In addition, an overview of several specific metabolic pathways and enzymatic activities used as targets against Cryptosporidium is provided. These metabolic processes include glycolytic pathways, fatty acid production, kinase activities, tRNA elaboration, nucleotide synthesis, gene expression and mRNA maturation. As a conclusion, we highlight emerging future strategies for screening natural compounds and assessing drug resistance issues.