In the present study, one of the targets present on the envelopes of coronaviruses, membrane glycoprotein (M) was chosen for the design of a multi-epitope vaccine by Immunoinformatics approach. The B-cell and T-cell epitopes used for the construction of vaccine were antigenic, nonallergic and nontoxic. An adjuvant, β-defensin and PADRE sequence were included at the N-terminal end of the vaccine. All the epitopes were joined by linkers for decreasing the junctional immunogenicity. Various physicochemical parameters of the vaccine were evaluated. Secondary and tertiary structures were predicted for the vaccine construct. The tertiary structure was further refined, and various parameters related to the refinement of the protein structure were validated by using different tools. Humoral immunity induced by B-cells relies upon the identification of antigenic determinants on the surface of the vaccine construct. In this regard, the vaccine construct was found to consist of several B-cell epitopes in its three-dimensional conformation. Molecular docking of the vaccine was carried out with TLR-3 receptor to study their binding and its strength. Further, protein–protein interactions in the docked complex were visualized using LigPlot+. Population coverage analysis had shown that the multi-epitope vaccine covers 94.06% of the global population. The vaccine construct was successfully cloned in silico into pET-28a (+). Immune simulation studies showed the induction of primary, secondary and tertiary immune responses marked by the increased levels of antibodies, INF-γ, IL-2, TGF-β, B- cells, CD4+ and CD8+ cells. Finally, the vaccine construct was able to elicit immune response as desired. Communicated by Ramaswamy H. Sarma

The best therapeutic strategy to find an effective vaccine against SARS-CoV-2 is to explore the target structural protein. In the present study, a novel multi-epitope vaccine is designed using in silica tools that potentially trigger both CD4 and CD8 T-cell immune responses against the novel Coronavirus. The vaccine candidate was designed using B and T-cell epitopes that can act as an immunogen and elicits immune response in the host system. NCBI was used for the retrieval of surface spike glycoprotein, of novel corona virus (SARS-CoV-2) strains. VaxiJen server screens the most important immunogen of all the proteins and IEDB server gives the prediction and analysis of B and T cell epitopes. Final vaccine construct was designed in silico composed of 425 amino acids including the 50S ribosomal protein adjuvant and the construct was computationally validated in terms of antigenicity, allergenicity and stability on considering all critical parameters into consideration. The results subjected to the modeling and docking studies of vaccine were validated. Molecular docking study revealed the protein-protein binding interactions between the vaccine construct and TLR-3 immune receptor. The MD simulations confirmed stability of the binding pose. The immune simulation results showed significant response for immune cells. The findings of the study confirmed that the final vaccine construct of chimeric peptide could able to enhance the immune response against nCoV-19.

Coronavirus disease 2019 (COVID-19), a highly contagious disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has drastically changed the lifestyle of people around the globe. Due to the lack of specific and effective antiviral drugs, transmission of the disease increases exponentially and makes it more serious and harder to control. Drugs that were assumed to be effective against COVID-19 have failed in various stages of clinical trials and this made the scientific community more disappointed. But, the race of researchers for developing new and effective antiviral to stop the disease progression still continues and our work is one among them. This study is an attempt to analyze the action of Tectoquinone and Acteoside; an important phytocompound, on SARS-CoV2 viral protease via in silico approach. The compounds were selected on the basis of their molecular docking values and they were subjected to molecular dynamics simulations about 50 ns to determine the stability and the thermodynamic feasibility between the target and the ligands. Binding energies like hydrogen bonding, hydrophobic and electrostatic interactions of the complexes were determined after MD simulations. The Pharmacokinetics and drug likeness evaluation of the compounds provide a strong evidence for the use of these compounds in developing drugs for clinical trials. Thus, the current study reveals the potential phytoconstituents present in Tectona grandis Linn to inhibit COVID-19 viral protease and thereby act as a lead therapeutic agent. Communicated by Ramaswamy H. Sarma

CRISPR genome editing utilizes Cas9 nuclease and single guide RNA (sgRNA), which directs the nuclease to a specific site in the genome and makes a double-stranded break (DSB). Design of sgRNA for CRISPR-Cas targeting, and to promote CRISPR adaptation, uses a regulatory mechanism that ensures maximum CRISPR-Cas9 system functions when a bacterial population is at highest risk of phage infection. Acinetobacter baumannii is the most regularly identified gram-negative bacterium infecting patients. Recent reports have demonstrated that the extent of diseases caused by A. baumannii is expanding and, in a few cases, now surpasses the quantity of infections caused by P. aeruginosa. Most Acinetobacter strains possess biofilm-forming ability, which plays a major role in virulence and drug resistance. Biofilm bacteria use quorum sensing, a cell-to-cell communication process, to activate gene expression. Many genes are involved in biofilm formation and the mechanism to disrupt the biofilm network is still not clearly understood. In this study, we performed in silico gene editing to exploit the AbaI gene, responsible for biofilm formation. The study explored different tools available for genome editing to create gene knockouts, selecting the A. baumannii AbaI gene as a target.

Background: ATP-binding cassette (ABC) transporters constitute one of the largest transporter protein families and play a role in diverse biological processes. Results: In the present study, bacteriocin isolated from the Enterococcus casseliflavus MI001 strain was identified as an ABC transporter ATP-binding protein. The optimal conditions for the production of bacteriocin were found to be at 35 °C, a pH 5.5, and an incubation time of 24 h. Purification was performed using ammonium sulphate precipitation, gel filtration, and DEAE ion exchange chromatography. The bacteriocin was purified with an eightfold purification scheme resulting with a specific activity of 15,000 AU/mg. The NMR spectrum of purified bacteriocin revealed the presence of amino acids, namely lysine, methionine, cysteine, proline, threonine, tryptophan, and histidine. Further, the bacteriocin ABC transporter showed antimicrobial activity against food spoilage microorganisms. Conclusions: The ABC transporter ATP-binding protein could be used as a potential alternative for food preservation, and it may be considered as a bio-preservative agent in food processing industries.