Brucellosis in livestock and its transmission to humans through the consumption of contaminated dairy products is an important issue. In this study, five immunogenic proteins were obtained from a 2DE gel analysis of Brucella abortus proteome after interaction with infected cattle's serum antibodies. These five proteins, MOXR family ATPase-α2, T9SS C-terminal Target domain-containing protein, Cobyric acid synthase, Hypothetical Protein, and Vir-B11 type IV Secretion Protein were introduced to the Brucella abortus proteome by MALDI-TOF MS/MS spectroscopy and then, analyzed with Mascot. Bioinformatics was applied to predict B and T cell epitopes, which were then randomly linked together to design a novel recombinant multi-epitope protein. The synthesized construct was transferred to E. coli BL21 and the expressed protein (ABOR) contained 549aa was confirmed with specific antibodies in infected cattle's serum.

HIGHLIGHTS

• Immunomics results of Brucella abortus demonstrated five immunogenic proteins.
• Antigenic epitopes were predicted and cloned in the pET22b expression vector.
• The expressed polypeptide was confirmed by interaction with antibodies in infected cattle's sera.

West Nile virus (WNV) and Japanese Encephalitis virus (JEV) are two major mosquito-borne flaviviruses that share almost similar symptoms after infection, e.g., flu-like symptoms. Though JEV is the most common cause of encephalitis (brain inflammation), recent studies have discovered approximately 30% involvement of the WNV in this. Furthermore, both viruses share similar genetic constituents with more than 70% homology. Therefore, these two viruses sometimes cause misdiagnosis due to their co-circulation with the same vector, and no solid protective treatment has yet been discovered against them. As a result, in this study, we used small interfering RNAs to provide dual protection against both viruses. The siRNAs have high demand as a potential treatment option for genetic treatments, and antiviral or antibacterial therapeutics for many diseases. In this study, we concluded that a single highly potent siRNA (5'-UCUCUUUCCCAUCAUGUUGUA-3') could be effective in silencing the coding sequences (CDS) of both WNV and JEV by utilizing several computational assays such as GC content, free energy of binding, free energy of folding, melting temperature, siRNA efficacy prediction, and molecular docking. After structural analysis (molecular modeling and docking), we found that this siRNA effectively binds with the human Argonaute-2 (AGO2) protein. Consequently, this siRNA could be a potential therapeutic development target against both viruses by silencing the CDS. Our research aims to develop genome-level therapies. The results can be applied to develop RNA molecules as a drug against WNV and JEV.

HIGHLIGHTS

• Promising siRNA target identified for dual protection against WNV and JEV.
• Efficient siRNA molecule S2 shows high binding affinity with human AGO2 protein.
• siRNA targeting NS5 gene shows promise for treating WNV and JEV-mediated infections.

Cyanobacteria and microalgae are promising sources of valuable bioactive compounds for nutraceutical and pharmaceutical applications. Proteins and peptides derived from these microorganisms have been shown different biological actions, including antioxidant and antimicrobial activities. In this study, Desmodesmus sp. protein extract was digested using two proteases, including bacterial protease with optimum activity in alkaline conditions and pepsin with optimum activity in acidic pH. The peptide mixtures derived from protease hydrolysis were evaluated by DPPH assay for antioxidant activity and microdilution antimicrobial assay. The results showed that peptides derived from both pepsin and bacterial protease digestions enhanced the antioxidant activity and these samples had between 80-100% antioxidant activities. In addition, pepsin digestion could reduce the MIC against S. aureus and methicillin-resistant S. aureus (MRSA) twofold compared to the initial protein extract before digestion. In conclusion, the peptides derived from enzymatic digestion of Desmodesmus sp. protein extract had promising biological activities that need further studies to identify the most bioactive peptide.

HIGHLIGHTS

• Desmodesmus protein extract was digested with different types of protease.
• Digestion of protein extract by pepsin and bacterial protease resulted in enhanced antioxidant activity.
• Digestion by the bacterial protease from Bacillus licheniformis resulted in bioactive peptides.

BMPs belong to transforming growth factor β superfamilies, which their principal role is inducing bone and cartilage formation at heterotopic and orthotopic sites. Since the formation of inclusion bodies is the main limitation of producing these proteins in Escherichia coli, in this study, the small ubiquitin-like modifiers (SUMO) fusion system was employed to improve solubility and expression of recombinant human BMP-7 (rhBMP-7) in E. coli. The SUMO fusion system has the ability to enhance protein expression, reduce target protein proteolytic degradation, and increase protein folding and solubility. In the current study, the SUMO protein gene was fused to the N-terminus of the BMP-7 gene, and cloned in the pET-28a vector. After purification of the expressed SUMO-BMP-7 protein by Ni-NTA chromatography, SUMO was removed from the BMP-7 protein using SUMO protease. In the second step of purification using Ni-NTA chromatography, the cleaved BMP-7 protein was purified and then identified by Western blot analysis. The results of the current study demonstrated that the SUMO fusion system is able to increase the soluble form of rhBMP-7. Furthermore, rhBMP-7 can be purified by a two-step purification strategy including: 1) purification of SUMO-BMP-7 and 2) purification of rBMP-7 after cleavage using Ni-NTA chromatography. Altogether, this research has provided a feasible approach for large-scale production of soluble rhBMP-7, to facilitate its further medical development.

HIGHLIGHTS

• SUMO is a well characterized family of ubiquitin-like molecules.
• SUMO fusion led to increased expression and solubility of BMP-7.
• BMP-7 is involved in the process of bone formation.

The snake venom is a potent source of a variety of drugs and therapeutic components. This study aimed to isolate and characterize some of proteins in Montivipera raddei venom. The protein bands and spots obtained by SDS-PAGE and two-dimensional electrophoresis were analyzed. The separated protein spots based on isoelectric point and molecular weight were scattered in the 15 to 66 kDa ranges and pI from 5 to 8. Six proteins was more extensively characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/TOF) analysis. These characterized proteins included Zinc metalloproteinase-disintegrin-like ecarin, L-amino-acid oxidase, metalloproteinase kistomin, Thiamine-monophosphate kinase, Ancrod, Acidic phospholipase A2.

HIGHLIGHTS

• Identification of several proteins from Montivipera raddei venom.
• Characterization of the six high concentrated proteins by MALDI-TOF/TOF spectroscopy in venom.
• Zinc metalloproteinase-disintegrin-like ecarin, L-amino-acid oxidase, metalloproteinase kistomin, Thiamine-monophosphate kinase, Ancrod, Acidic phospholipase A2 were identified in venom of Montivipera raddei.

Luciferase is a well-known oxidative enzyme that produces bioluminescence. The Pseudomonas meliae is a plant pathogen that causes wood to rot on nectarine and peach and possesses a luciferase-like monooxygenase. After activation, it produces bioluminescence, and the pathogen’s bioluminescence is a visual indicator of contaminated plants. The present study aims to model and characterize the luciferase-like monooxygenase protein in P. meliae for its similarity to well-established luciferase. In this study, the luciferase-like monooxygenase from P. meliae infects chinaberry plants has been first modeled and then, studied by comparing it with existing known luciferase. In addition, the similarities between uncharacterized luciferase from P. meliae and the template from Geobacillus thermodenitrificans were analyzed. The results suggest that the absence of bioluminescence in P. meliae could be critical for the production of the luciferin substrate and the catalytic activity of the enzyme due to the evolutionary mutation in positions 138 and 311. The active site remains identical except for two amino acids. Therefore, mutation of the residues 138 and 311 in P. meliae Luciferase-like monooxygenase may restore luciferase light-emitting ability.

HIGHLIGHTS

• Structural characterization of luciferase-like monooxygenase in P. meliae.
• Bioluminescence can be used to evaluate antimicrobial efficacy by releasing light emissions.
• Luciferase-like monooxygenase: a potential therapeutic candidate for clinical applications.

Mumijo is a traditional drug that has been used in traditional medicine for a long time and its aqueous extract is used for the treatment of osteoporosis and bone fractures. Besides, in modern medicine, nano-sized hydroxyapatite (nHA) has achieved immense attention for bone integration and regeneration of bony defects treatment. Since the frequency of accidental bone disorders and damage is growing worldwide, the need for artificial bone implants is increasing. Thus, in this study, the fibrillar beta-lactoglobulin (BLG)-Mumijo-nHA complex was synthesized and characterized by UV–Visible, fluorescence, Fourier transform infrared, circular dichroism spectroscopy, scanning electron microscopy, and zeta potential analysis. The results showed that the fibrillar BLG-Mumijo-nHA complex was formed. The results also confirmed that the complex had a negative surface charge and was moderately stable. Cell viability assays indicated that fibrillar BLG-Mumijo-nHA complex induced bone marrow-derived mesenchymal stem cell growth at higher concentrations. Although further experiments are warranted to draw firm conclusions, it could be proposed that the fibrillar BLG-Mumijo-nHA complex could be a good candidate for the treatment of osteoporosis and bone fractures.

Highlights

• The fibrillar BLG-Mumijo-nHA complex was synthesized in detail.
• UV-Visible, fluorescence emission, and CD spectroscopy as well as z-potential value confirmed the formation of a complex.
• The complex could be a good candidate for tissue engineering.

The Programmed cell death ligand-1 (PD-L1), an immune checkpoint molecule, is the ligand of Programmed cell death protein 1 (PD-1). They are crucial molecules in maintaining immune homeostasis. PD-L1/PD-1 axis regulates the initiation and maintenance of tolerance and protects tissues from autoimmune responses; however, cancer cells can use the PD-1/PD-1 axis to evade the anti-tumor response of immune cells. Increased PD-L1 expression is directly associated with poor prognosis in hepatocellular carcinoma (HCC). Although immunotherapy with immune checkpoint inhibitors (ICIs) are leading therapy in cancer treatment, using biomarkers to regulate immune checkpoints at the RNA level is considered a promising tool in novel therapeutic approaches. Increasing evidence has reported that miRNAs are critical regulators of tumor development. Hence, we performed a current systematic review to explore PD-L1 inhibiting miRNAs involved in hepatocellular carcinoma. Five databases were systemically searched to obtain the relevant original articles. Consequently, seventeen studies were included in the current systematic review. According to obtained literatures, some microRNAs, namely miR-194-5p, -675-5p, 194-5p, -1, -455-5p, -223-3p, -513, -195, -506, -329-3p, -424, -411-5p, -182-5p, -200, -378a-3p, -570, -200c, and -513a-5p can inhibit PD-L1 expression in HCC cells. These can ultimately reduce tumor proliferation, inhibit tumor migration, stimulate the chemosensitivity of cancer cells, and induce apoptosis in tumor cells. Moreover, the investigated miRNAs were further analyzed using miRNA target prediction online tools to highlight the future direction of their functions in HCC.

HIGHLIGHTS

• Cancer cells can use the PD-1/PD-1 axis to evade the anti-tumor response of immune cells.
• Increased PD-L1 expression is directly associated with poor prognosis in hepatocellular carcinoma.
• Several microRNAscan inhibit PD-L1 expression in HCC cells.

The Trends in Peptide and Protein Sciences is a peer-reviewed, online-only (previously print-online), scientific journal owned by Protein Technology Research Center, Shahid Beheshti University of Medical Sciences and documents in all important aspects of the research in peptides and proteins focusing on analytics and impurities, bioinformatics, biopharmaceuticals and vaccines, biotechnology, chemical synthesis, conformational analysis, design and  development of protein therapeutics, determination of structure, enzymology, folding and sequencing,  formulation and stability, function, genetics,  immunology, kinetics, modeling, molecular biology, pharmacokinetics and pharmacodynamics of therapeutic proteins and antibodies, pharmacology,  protein engineering and development, protein-protein interaction, proteomics, purification/expression/production, simulation, thermodynamics and  hydrodynamics and protein biomarkers. The aim of this Journal is to publish high quality original research articles, reviews, short communications and letters and to provide a medium for scientists and researchers to share their findings from the area of peptides and proteins. The Trends in Peptide and Protein Sciences is published in collaboration with Iranian Association of Pharmaceutical Scientists. From volume 3 (2018) of TPPS, articles are continuously published online only, as soon as the review process is completed.