The Toxoplasma gondii calcium-dependent protein kinase-3 (CDPK3) is a key enzyme for parasite egress, control of calcium-dependent permeabilization in parasitophorous vacuole membrane and tissue cyst formation. In this study, we comprehensively explored the bioinformatics features of this protein to improve vaccine design against T. gondii. Materials and Methods: Various web servers were employed for the analysis of physicochemical properties, post-translational modifications, localization in the subcellular milieu, secondary and tertiary structures, as well as B-cell, major histocompatibility complex (MHC)binding and cytotoxic T-lymphocyte (CTL) epitopes. Results: This protein was a 537 amino acid antigenic and non-allergenic molecule with a molecular weight of 60.42 kDa, a grand average of hydropathicity score of-0.508, and aliphatic index of 79.50. There exists 46.74% alpha helix, 12.48% extended strand, and 40.78% random coil in the secondary structure. Ramachandran plot of the refined model demonstrated 99.3%, 0.7%, and 0.0% of residues in the favored, allowed and outlier areas, respectively. Besides, various potential B-cell (continuous and conformational), MHC-binding and CTL epitopes were predicted for Toxoplasma CDPK3 protein. Conclusion: This article provides a foundation for further investigations, and laid a theoretical basis for the development of an appropriate vaccine against T. gondii infection.

The angiotensin-converting enzyme 2 (ACE2) and main protease (MPro), are the putative drug candidates for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). In this study, we performed 3D-QSAR pharmacophore modeling and screened 1,264,479 ligands gathered from Pubchem and Zinc databases. Following the calculation of the ADMET properties, molecular docking was carried out. Moreover, the de novo ligand design was performed. MD simulation was then applied to survey the behavior of the ligand-protein complexes. Furthermore, MMPBSA has utilized to re-estimate the binding affinities. Then, a free energy landscape was used to find the most stable conformation of the complexes. Finally, the hybrid QM-MM method was carried out for the precise calculation of the energies. The Hypo1 pharmacophore model was selected as the best model. Our docking results indicate that the compounds ZINC12562757 and 112,260,215 were the best potential inhibitors of the ACE2 and MPro, respectively. Furthermore, the Evo_1 compound enjoys the highest docking energy among the designed de novo ligands. Results of RMSD, RMSF, H-bond, and DSSP analyses have demonstrated that the lead compounds preserve the stability of the complexes’ conformation during the MD simulation. MMPBSA data confirmed the molecular docking results. The results of QM-MM showed that Evo_1 has a stronger potential for specific inhibition of MPro, as compared to the 112,260,215 compound.

Background. This research was aimed at evaluating the seroprevalence of acute and chronic Toxoplasma gondii (T. gondii) infection in pregnant women and related risk factors in southwest Iran. Methods. In this cross-sectional study, eighty-eight pregnant women were included from October 2019 to December 2019. The presence of anti-T. gondii IgM and IgG antibodies was measured using the enzyme-linked immunosorbent assay (ELISA). In addition, a questionnaire consisting of demographic information was completed for each subject. Results. The overall seroprevalence of T. gondii infection was estimated to be 34.09% (30/88). Of these, 1 (1.13%) and 29 (32.95%) samples were found positive for IgM and IgG, respectively. Regarding the risk factors, the consumption of raw/undercooked meat ( P value = 0.007) and history of abortion ( P value = 0.017) were significantly associated with IgG seroprevalence in pregnant women. Conclusion. The results showed that the pregnant women of southwest Iran might be moderately exposed to T. gondii. Since the risk of acute T. gondii infection in this susceptible group is very important, regular screening tests to diagnose the infection are recommended before pregnancy.

Purpose. The probable association between Toxoplasma gondii (T. gondii) infection and diabetes mellitus (DM) is still controversial, and there are several studies with conflicting results. Thus, this study was performed to assess the possible association between chronic T. gondii infection and type 1 diabetes mellitus (T1DM) and T2DM. Methods. In this case-control study, a total of 105 diabetic subjects including 36 patients with T1DM and 69 patients with T2DM were recruited. In addition, 150 nondiabetic subjects were enrolled as controls. Each case group had its own control group. Each participant completed a structured questionnaire obtaining demographic information. Serum samples were examined for T. gondii-specific IgG antibody using enzyme-linked immunosorbent assay (ELISA) method. Results. Analysis revealed that 69.4% and 34.0% of patients with T1DM and control subjects were serologically positive for T. gondii, respectively (odds ratio (OR): 4.41; 95% confidence interval (CI): 1.75–11.06; P = 0.001 ). Moreover, 72.5% of T2DM patients and 29.0% of healthy individuals were seropositive for T. gondii (OR: 6.44; 95% CI: 3.25–12.74; P < 0.001 ). Among risk factors, only contact with cats was significantly associated with IgG seroprevalence in both T2DM patients ( P < 0.001 ) and control subjects ( P = 0.045 ). Conclusion. Although the results showed that chronic T. gondii infection is significantly associated with T1DM and T2DM, there remain many questions regarding the exact mechanisms of T. gondii in the pathogenesis of DM.

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