Identification of a potent dual-function inhibitor for hIMPDH isoforms by computer-aided drug discovery approaches.

Inosine monophosphate dehydrogenase (IMPDH) is a key enzyme in de novo biosynthesis of purine nucleotides. Due to this important role, it is a great target to drug discovery for a wide range of activities, especially immunosuppressant in heart and kidney transplantation. Both human IMPDH isoforms are expressed in stimulated lymphocytes. In addition to the side effects of existing drugs, previous studies have mainly focused on the type II isoform. In this study, virtual screening and computer-aided approaches were employed to identify potential drugs with simultaneous inhibitory effects on both human IMPDH isoforms. After Re-docking, Double-step docking, and identification of virtual hits based on the PLANTS scoring function, drug-likeness and ADME-Tox assessments of the topmost ligands were performed. Following further evaluation, the best ligand was selected and, in complex with both isoforms, simulated in monomeric and tetrameric forms using molecular dynamics to evaluate its stability and binding pattern. The results showed a potential drug candidate [(S)-N-(3-hydroxy-1-(4-hydroxyphenyl) propyl)-2-(3-methyl-2,4-dioxo-3,4-dihydropyrimidin-1(2H)-yl) acetamide] with a high inhibitory effect on the two human IMPDH isoforms. This drug-like inhibitor could potentially serve as an immunosuppressant to prevent transplant rejection response by inhibiting B- and T-lymphocyte proliferation. In addition, its effect can be evaluated in various therapeutic targets in which IMPDH is known as a therapeutic target, especially in Covid-19 patients.

Appraisal of SARS-CoV-2 mutations and their impact on vaccination efficacy: an overview.

With the unexpected emergence of the novel 2019 Wuhan coronavirus, the world was faced with a sudden uproar that quickly shifted into a serious life-threatening pandemic. Affecting the lives of the global population and leaving drastic damage in various sections and systems, several measures have been constantly taken to tackle down this crisis. For instance, numerous vaccines have been developed in the past two years, some of which have been granted emergency use, thus providing sufficient immunity to the vaccinated individuals. However, the appearance of newly emerged SARS-CoV-2 variants with accelerated transmission and fatality has led the world towards another pandemic. Having undergone various mutations in genomic and/or amino acid profiles, some of the emerged variants of concern (VOCs) including Alpha, Beta, Gamma, and Delta have displayed immune evasion and pathogenicity even in the vaccinated population, hence raising concerns regarding the efficacy of current vaccines against new VOCs of COVID-19. Therefore, genomic investigations of SARS-CoV-2 mutations are expected to provide valuable insight into the evolution of SARS-CoV-2, while also determining the impact of different mutations on infection severity. This study was constructed with the aim of shining light on recent advances regarding mutations in major COVID-19 VOCs, as well as vaccination efficacy against those VOCs.

Depinar, a drug that potentially inhibits the binding and entry of COVID-19 into host cells based on computer-aided studies.

BACKGROUND AND PURPOSE: The new coronavirus (Covid-19) has resulted in great global concerns. Due to the mortality of this virus, scientists from all over the world have been trying to employ different strategies to tackle down this concern. This virus enters cells via phagocytosis through binding to the angiotensin-converting enzyme II receptor. After invading the body, it can stay hidden in there for a period of up to 24 days (incubation period). EXPERIMENTAL APPROACH: In this report, by the use of in silico studies we selected several FDA-approved compounds that possess antiviral properties. We chose the viral Spike protein as the target of drug compounds and carried out the screening process for the FDA databank in order to find the most effective ligand. FINDINGS/RESULTS: The results from dock and MD revealed 10 compounds with high affinity to the receptor-binding domain motif of S protein. The best inhibitors were the ingredients of Depinar, which managed to effectively block the interactions between cells and virus. CONCLUSION AND IMPLICATION: The results of this study were approved by in silico studies and due to the lack of time; we did not test the efficiency of these compounds through in vitro and in vivo studies. However, the selected compounds are all FDA approved and some are supplements like vitamin B12 and don't cause any side effects for patients.