Molecular docking of immunogenic peptide ofToxoplasma gondiiand encapsulation with polymer as vaccine candidate

Abstract

Toxoplasma gondii is one of the most widely spread parasitic organisms in the world. T. gondii causes primary, chronic infection and mortality. Major surface antigen 1 is the most abundant tachyzoite surface protein and highly conserved between species and causes strong humoural response. Some studies showed that the peptide sequence of surface antigen has immunity. Therefore, tachyzoite surface antigenic peptide sequence is one of the good candidates for vaccine development. However, conformational information and delivery systems are very important parameters for vaccine development. Computational chemistry which is used as an effective method to perform drug or vaccine design provides important information on structure-activity relationship, biological effects of functional groups, molecular geometry, design of enzyme inhibitors and antagonists. The interaction of immunological peptides with protein systems was carried out by means of computing the free energy of binding using the molecular docking technique. Due to the major histocompatibility complex (MHC), proteins play a substantial role for adaptive immunity, the crystal structure of a MHC class I, which plays a pivotal role in the adaptive branch of the immune system, was preferred for docking calculations. A delivery system based on poly(lactic-co-glycolic acid) (PLGA) nanoparticles and peptide loaded PLGA nanoparticles was prepared in this study to improve the bioavailability of tachyzoite surface antigenic peptide sequence. Double emulsion method (water-in-oil-in-water or w/o/w) was used for synthesis of PLGA and peptide loaded PLGA nanoparticles. The average particle size, polydispersity index and zeta potential values of PLGA and peptide loaded PLGA nanoparticles were measured with zeta-sizer by using dynamic light scattering (DLS) technique. The scanning electron microscope (SEM) (Zeiss Supra 50 V) was used for imagining the peptide loaded PLGA nanoparticles. Cell toxicity of nanoparticles was assayed on AGS (gastric adenocarcinoma) cell line. To evaluate mitochondrial activity of cells and toxicity studies, XTT methods were carried out. In this study, we aimed to obtain specific immunological peptide loaded PLGA nanoparticles and characterize the formation with FTIR, zeta sizer and SEM imaging, and evaluate cytotoxicity and carry out molecular docking calculations of peptide-MHC protein in order to enlight in vivo events as vaccine candidate against T. gondii.

Piperine Nanoparticles for Topical Application: Preparation, Characterization,In vitroandIn silicoEvaluation

“…The binding affinities and RMSD values between piperine and COX‐1 (1PRH, 4O1Z) and COX‐2 (4COX, 3NTB) were also tabulated in Table . All calculated RMSD values are consistent with the literature values . The best docking structures between piperine and COX‐1 and COX‐2 were also seen in Figure , and Figure .…”

A combined application of molecular docking technology and indirect ELISA for the serodiagnosis of bovine tuberculosis

“…The evaluation of the results of docking prediction mainly analyzes the RMSD value of the docking compound. The RMSD value is the most commonly used indicator in structural modeling and prediction, used to measure the degree of difference between two or more structural data [ 26 ]. The smaller the RMSD value, the more reliable the modeling or prediction results.…”

Biocompatibility of Poly[di(carboxylatophenoxy)-phosphazene] Polymer: In Vitro Cytotoxicity in Cell Culture

“…Cells were incubated at 37 °C with 5% CO 2 for 24 h. The medium in the plate was removed, and 100 µL of XTT solution (4 mg tetrazolium salt had dissolved in 10 ml cell culture medium with 10 µL PMS) was added to each well. Cells were incubated for 4 h, and absorbance was measured by multiple readers (Labline) at 450 nm [17].…”