Karim Mahnam

Background: The SARS-CoV-2 virus is a new highly contagious Coronavirus with a positive-sense RNA encoding 16 non-structural proteins (nsps16, nsp15, nsp3). In this study, the coronavirus pathogenicity and the losartan functional ligand for inhibiting TRPM2 and macrodomain have been molecularly evaluated.Material and method: In this study, the structures of macrodomain binding ADP ribose in CoVs and human Transient Receptor Potential Cation Channel Subfamily M Member 2 (TRPM2) protein were downloaded from protein data bank. Then, a virtual screening was done to recognize the hit compounds from GalaXi_2019-10, KnowledgeSpace_2019-05, and REALspace_2019-12 databases. This collection, then, was imported to the ligandScout software, on the base of Adenosine Diphosphate Ribose (ADPR) pharmacophore model. Result: Among seven compounds, five compounds were finally evaluated as the structural analogs of ADPR or other nucleotides, from which one compound was a non-FDA-approved sulphonamide and was removed. The other compound, losartan, was finally selected for molecular docking and molecular dynamic simulation. According to the virtual screening and docking, losartan was candidate as an effective ligand for TRPM2 and macrodomain. Conclusion: In the current study losartan earned a proper dock score and binding affinity to create the complexes with TRPM2 and macrodomain. The inhibitory effect of losartan on PARP has been shown and it could interfere positively in several points (PARP, PARG- macrodomain and TRPM2) and decreases oxidative stress and apoptosis in COVID-19.

Multiple sclerosis (MS), as one of the human autoimmune diseases, demyelinates the neurons of the central nervous system (CNS). Activation of the T cells which target the CNS antigens is the first autoimmune event in MS. Myelin oligodendrocyte glycoprotein (MOG) and myelin basic protein (MBP) are two proteins of the myelin sheath and have been shown to be among the high antigens contributing to the pathogenesis of MS. Production of the drugs with high specificity for the immune system diseases is a concern for various researchers. Therefore, tolerogenic vaccines are considered as a new strategy for the treatment of MS by presenting specific antigens. This study aimed to design and compare two fusion proteins by a combination of two neuroantigens linked to interleukin-16 (IL-16) (MOG-Linker-MBP-IL16 and MBP-Linker-MOG-IL16) as vaccines for MS. In this study, at first two models MOG (aa 11-30) linked to MBP (aa 13-32) was made by Modeler 9.10 and simulated for 20 ns via Gromacs 5.1.1 package. Then simulated antigen domains connected to the N-terminal domain of IL-16 and obtained structures simulated for 50 ns. The results revealed that both constructs had stable structures and the linker could keep two antigenic fragments separate enough, preventing undesired interactions. While MOG-Linker-MBP-IL16 showed better solubility, more accessible surface areas, more flexibility of its IL-16 domain, and better functionality of its IL-16 domain as well as more specific cleavage of its related epitopes after endocytosis lead to a better presentation of its antigenic property.

Aspartame (L-Aspartyl-L-phenylalanine methyl ester) is a sweet dipeptide used in some foods and beverages. Experimental studies show that aspartame causes osteoporosis and some illnesses, which are similar to those of copper and calcium deficiency. This raises the issue that aspartame in food may interact with cations and excrete them from the body. This study aimed to study aspartame interaction with calcium, zinc, iron, sodium, and cadmium ions via molecular dynamics simulation (MD) and spectroscopy. Following a 480-ns molecular dynamics simulation, it became clear that the aspartame is able to sequester Fe²⁺, Ca²⁺, Cd²⁺, and Zn²⁺ ions for a long time. Complexation led to increasing UV–Vis absorption spectra and emission spectra of the complexes. This study suggests a potential risk of cationic absorption of aspartame. This study suggests that purification of cadmium-polluted water by aspartame needs a more general risk assessment.