Exploring dengue proteome to design an effective epitope-based vaccine against dengue virus

Dengue, a mosquito-borne disease, is caused by four known dengue serotypes. This infection causes a range of symptoms from a mild fever to a sever homorganic fever and death. It is a serious public health problem in subtropical and tropical countries. There is no specific vaccine currently available for clinical use and study on this issue is ongoing. In this study, bioinformatics approaches were used to predict antigenic, immunogenic, non-allergenic, and conserved B and T-cell epitopes as promising targets to design an effective peptide-based vaccine against dengue virus. Molecular docking analysis indicated the deep binding of the identified epitopes in the binding groove of the most popular human MHC I allele (human leukocyte antigens [HLA] A*0201). The final vaccine construct was created by conjugating the B and T-cell identified epitopes using proper linkers and adding an appropriate adjuvant at the N-terminal. The characteristics of the new subunit vaccine demonstrated that the epitope-based vaccine was antigenic, non-toxic, stable, and soluble. Other physicochemical properties of the new designed construct including isoelectric point value, aliphatic index, and grand average of hydropathicity were biologically considerable. Molecular docking of the engineered vaccine with Toll-like receptor 2 (TLR2) model revealed the hydrophobic interaction between the adjuvant and the ligand binding regions in the hydrophobic channel of TLR2. The study results indicated the high potential capability of the new multi-epitope vaccine to induce cellular and humoral immune responses against the dengue virus. Further experimental tests are required to investigate the immune protection capacity of the new vaccine construct in animal models.

Communicated by Ramaswamy H. Sarma     

RETRACTED ARTICLE: Serum Zinc and Adiponectin Levels in Patients with Polycystic Ovary Syndrome,Adjusted for Anthropometric,Biochemical, Dietary Intake,and Physical Activity Measures

Biological Trace Element Research -     

Risk of coronary artery stenosis in Iranian type 2 diabetics: is there a role for matrix metalloproteinase-3 gene (-1612 5A/6A) polymorphism?

Aim  

To investigate the association of matrix metalloproteinase-3 (MMP-3) polymorphism with susceptibility to coronary artery stenosis (CAS) and the number of diseased vessels in patients with type 2 diabetes mellitus (T2DM).     

In silico Analysis of Different Signal Peptides for the Excretory Production of Recombinant NS3-GP96 Fusion Protein in Escherichia coli

International Journal of Peptide Research and Therapeutics - Escherichia coli is one of the simplest hosts which is widely being used to express heterologous proteins. However, without appropriate...     

Characterization of an exported protease from Shiga toxin-producing Escherichia coli

The gene for a novel, high molecular weight protein secreted by Shiga toxin-producing Escherichia coli (STEC) has been cloned, sequenced and characterized with respect to its activity. This gene, designated pssA , is localized on the large plasmid that also harbours the STEC haemolysin operon. Sequencing of a region comprising 10 630 nt revealed that the sequences flanking the pssA gene are composed of several remnants of different insertion elements. The PssA protein is produced as a 142 kDa precursor molecule that, after N- and C-terminal processing, is released into the culture supernatant as a mature polypeptide of approximately 104 kDa. The primary sequence of PssA is highly related to a family of autonomously transported putative virulence factors from different Gram-negative pathogens, which includes the Tsh protein of an avian-pathogenic E . coli strain, the SepA protein from Shigella flexneri and the EspC protein from enteropathogenic E . coli . A common motif present in all four proteins is reminiscent of the catalytic centre of certain serine proteases. PssA (protease secreted by STEC) indeed shows serine protease activity in a casein-based assay and is moreover cytotoxic for Vero cells. This activity of PssA and probably of other proteins of the Tsh family may be of functional importance during infection of the mucosal cell layer by the bacterial pathogen.     

Optimization of culture media for L-asparaginase production by newly isolated bacteria,Bacillus sp. GH5

The enzyme L-asparaginase has been extensively studied by many researchers mainly because of its considerable therapeutic properties. Producing a convenient quantity of L-asparaginase can be conducted either by discovering new microbial sources with higher enzyme production or by manipulating the medium components for known microbial sources. The present paper discusses the studies carried out in order to enhance the production of L-asparaginase by newly isolated bacteria, Bacillus sp. GH5. Based on the results obtained from media optimization studies, a modified media was developed for optimal L-asparaginase production. Concisely, screening of the nutrients using a proper statistical design showed that tapioca starch, gelatin, ammonium oxalate, CaCO₃, and L-asparagine were respectively the most important sources for carbon, organic nitrogen, inorganic nitrogen, mineral salt, and amino acids. The composition of the optimized medium was the following (per 1 L): 5.0 g L-asparagine; 0.5 g MgSO₄ · 7H₂O; 6.0 g NaHPO₄ · 2H₂O; 3.0 g (NH₄)₂C₂O₄; 0.5 g CaCO₃; 0.014 g CaCl₂ · 2H₂O; 2.0% w/v tapioca starch; 5.0 g gelatin; and 15.0 g agar.     

Changes in the activity of amylase, peroxidase and catalase in beech (Fagus orientalis Lipsky) during dormancy and growth

Activities of peroxidase, amylase and catalase were analyzed on beech (Fagus orientalis Lipsky) during one year to determine relationship between these enzymes with the period of dormancy and growing season. Results showed that amylase activity was high but catalase and peroxidase activities were low during the growing season. Peroxidase and catalase activities increased from July to November whereas amylase activity started to decrease at the same time, which means that the plants were prepared themselves to be dormant and the hardening was happened. The peroxidase maximum activity was in November, which is an important sign of dormancy and completing hardening in plant. The dormancy released from February along with decrease of catalase activity. At the beginning of growing season, correlation between amylase and catalase was increased. Amylase activity also increased gradually. No significant correlation between amylase-catalase and amylase-peroxidase activities was found at the period of dormancy. In our study, we found that the seasonal activity of enzymes such as peroxidase, catalase, and amylase, also correlation between these enzymes could be an important factor for the detection the period of dormancy and growing season.     

Novel biotechnology approaches in colorectal cancer diagnosis and therapy

With ever-increasing molecular information about colorectal cancer (CRC), there is an expectation to detect more sensitive and specific molecular markers for new advanced diagnostic methods that can surpass the limitations of current screening tests. Moreover, enhanced molecular pathology knowledge about cancer has led to the development of targeted therapies, designed to interfere with specific aberrant biological pathways in cancer. Furthermore, biotechnology has opened a new window in CRC diagnosis and treatment by introducing different application of antibodies, antibody fragments, non-Ig scaffold proteins, and aptamers in targeted therapy and drug delivery. This review summarizes the molecular diagnostic and therapeutic approaches in CRC with a focus on genetic and epigenetic alterations, protein and metabolite markers as well as targeted therapy and drug delivery by Ig-scaffold proteins, non-Ig scaffold proteins, nanobodies, and aptamers.