Tetrazoles as PPARγ ligands: A structural and computational investigation

Diabetes is an important chronic disease affecting about 10% of the adult population in the US and over 420 million people worldwide, resulting in 1.6 million deaths every year, according to the World Health Organization. The most common type of the disease, type 2 diabetes, can be pharmacologically managed using oral hypoglycemic agents or thiazolidinediones (TZDs), such as pioglitazone, which act by activating the Peroxisome Proliferated-Activated Receptor gamma. Despite their beneficial effects in diabetes treatment, TZDs like rosiglitazone and troglitazone were withdrawn due to safety reasons, creating a void in the pharmacological options for the treatment of this important disease. Here, we explored a structure-based approach in the screening for new chemical probes for a deeper investigation of the effects of PPAR gamma activation. A class of tetrazole compounds was identified and the compounds named T1, T2 and T3 were purchased and evaluated for their ability to interact with the PPAR gamma ligand binding domain (LBD). The compounds were binders with micromolar range affinity, as determined by their IC50 values. A Monte Carlo simulation of the compound T2 revealed that the tetrazole ring makes favorable interaction with the polar arm of the receptor binding pocket. Finally, the crystal structure of the PPAR gamma-LBD-T2 complex was solved at 2.3 angstrom, confirming the binding mode for this compound. The structure also revealed that, when the helix H12 is mispositioned, an alternative binding conformation is observed for the ligand suggesting an H12-dependent binding conformation for the tetrazole compound. (C) 2021 Elsevier Inc. All rights reserved.

Automated summary

Diabetes is a significant global health issue, with type 2 diabetes being the most common form. Pharmacological management often involves drugs like TZDs, although safety concerns have led to the withdrawal of certain medications. Researchers have identified a class of tetrazole compounds that show potential for interacting with PPAR gamma, providing new avenues for investigating diabetes treatment.