Modares Journal of Biotechnology

Abstract Introduction: Amyloid beta (Aβ) is the major constituent of harmful plaques in the Alzheimer’s patients. Thus, study of Aβ and understanding its related molecular and cellular mechanisms is essential for diagnosis and therapeutic interventions. This study introduces a rapid, simple, and cost-effective technique for production and purification of this peptide, utilizing the expression of Aβ gene within bacterial system.
Materials and methods: Aβ gene was synthesized and transferred into the expression vector pET26b. After induction by Lactose and 24 hours of incubation for Aβ expression the cell sediment was analyzed for presence of recombinant peptide using SDS-PAGE and Western blot. Then the purification of recombinant peptide was carried using nickel chloride affinity chromatography. Characterization of purified Aβ was performed by evaluating cell cytotoxicity in 25 µM and 50 µM concentrations using MTT assay on Alzheimer cell line model SH-SY5Y.
Results: Colony PCR and sequencing results showed the correct insertion of Aβ coding fragment into the expression vector. Presence of bands with the expected size in the results of SDS PAGE and western blot had confirmed successful expression of his-tagged recombinant peptide. MTT assay results showed the purified peptide has respectively 30 and 50% cytotoxicity for 25 µM and 50 µM concentrations.
Discussion: Production of amyloid beta peptide in bacterial hosts seems to be favorable. Obtaining Aβ peptide in soluble phase is an important advantage of this study. Hence according to toxicity of the purified peptide, it can be utilized for cell line treatments and further researches on Alzheimer disease.

Abstract The production of secondary metabolites of medicinal plant

Abstract Newcastle disease virus (NDV) causes one of the most dangerous infections in birds. High economic losses and high mortality are outcomes of this virus, which does not have any immediate cure. The natural reservoir of this virus can remain among bird and non-bird animals like farm animals. In Iran, this virus has reached a steady situation. Also, it should be mentioned that migrating birds can transfer the virus. The F protein of the virus is essential in pathogenicity and determination of pathogenic strain of NDVs, which has the regions that are essential in pathogenicity, immunogenicity, cell fusibility, and tissue necrosis. In this study, with computational analysis of this protein, some features related to this protein such as protein cleavage site, the conserved region in immunogenicity, infected species in Middle Eastern countries, and physicochemical properties of protein were determined. Results showed that the F protein of NDV consists of highly conserved regions that show a high rate of similarity and identity. Despite the majority of strains characterized as pathogenic, there were still non-pathogenic strains circulating in the Middle East. In this comprehensive study, protein regions essential in immunogenicity and epitope formation were identified, which may be used in the development of recombinant vaccines against this virus.

Abstract Researchers are currently directing their efforts toward developing new enzyme stabilization and enhancement strategies to broaden their application in various industries. This study utilized a unified platform to stabilize and safeguard proteins in industrial settings. Despite the wide-ranging industrial applications of lipases, their utility in industrial processes is limited by their susceptibility to degradation under harsh environmental conditions. In our study, we used a dual-purpose strategy that involved both enzyme stabilization and the shielding of an organosilica protective layer. After expressing and purifying the recombinant lipase enzyme, we immobilized it onto silica nanoparticles and shielded it with an organosilica nanolayer to protect the enzyme. We meticulously examined the optimal thickness of the protective layer and its influence on enzyme stabilization against environmental stressors. Our research findings demonstrate that the immobilized enzyme exhibited a remarkable level of stability compared to its free enzyme when subjected to various factors, such as fluctuations in temperature and exposure to chemical agents. Furthermore, the immobilized samples displayed optimal activity across a broad range of temperatures, highlighting this approach's adaptability and efficacy. Notably, the organosilica layer significantly bolstered the reactivity recovery of denatured proteins with SDS and urea, highlighting the versatile applications of this method. These findings indicated that our present platform has great potential to improve the efficiency and stability of industrial enzymes against various environmental challenges.

Abstract In recent years, targeted drug delivery systems have emerged as a promising approach to increase the efficacy and minimize side effects of therapeutic agents. Cerasomes are a special type of liposomes with covalent siloxane networks on the surface that provide exceptional morphological stability while retaining all the beneficial properties of liposomes. Cerosomes provide a unique platform for drug encapsulation and delivery due to their biocompatibility, stability, controllable release, and long-term storage. In this research, an attempt has been made to engineer the surface of cerosomes to increase the selectivity and efficiency of drug delivery. In such a way that the Herceptin antibody is placed on the surface of the serosa and allows the precise targeting of HER²⁺ cells. Then, the physicochemical characteristics of antibody-functionalized cerosomes, including size and surface charge 229±15.6 nm and 13.5±1.2 mV were respectively obtained. The results of IR and fluorescence spectrum showed that the antibody was successfully attached to the surface of cerasome with a binding efficiency of 64%. These results prove the basic mechanisms governing the synthesis of immunocerasomes and provide a valuable approach for future developments in targeted drug delivery systems.

Abstract Breast cancer is the most common cancer in women, and despite many scientific advances, it remains the leading cause of cancer-related death in women. To solve this global problem, deeper molecular studies in the field of breast cancer are needed. Nowadays, the role of piRNAs in various cancers is of great interest. In this study, we aim to identify important piRNAs involved in breast cancer. For this purpose, raw small RNA seq data related to cancerous and normal breast tissue samples were selected and extracted from the GEO database, and the Galaxy platform was used for their bioinformatic analysis. The differential expression of 372 piRNAs was obtained based on Log2 FC ≥ 2, p-value ≤ 0.05, of which 191 showed increased expression and 181 showed decreased expression. The highest increase is related to hsa-piR-33125, whose target is GATAD2A and plays a role in carcinogenesis processes such as blood vessel development, apoptosis, regulation of gene expression at the transcriptional level, etc. The largest decrease is related to hsa-piR-33073 with Log2 FC= -4.20. To find a list of important piRNAs that have a significant difference in expression in breast cancer compared to normal tissue, as well as to determine the increase or decrease of their expression in cancer tissue and to identify the target genes and investigate their role in the biological pathways involved in the development and progression of cancer. This can be the beginning of studies that will ultimately lead to advances in breast cancer research and treatment methods.

Abstract PFU DNA polymerse shows the lowest error rate in Polymerase Chain Reaction (PCR) but it seperates from DNA after about 20 nucleotides add to the end of primer strand. The research purpus is processivity improvement of PFU DNA polymerase by means of rational design and point mutation due to lowest enthropy and enthalpy costs. so DNA polymerases in B family with high processivity were selected and their structures and sequences were compared with PFU DNA polymerase then an optimized mutation was induced . Native form and mutant were simulated for 100 ns and the trajectories were analyzed. ΔG_binding was calculated by g_mmpbsa tool and proved that the mutant shows a robust affinity .

Abstract Tautomers are isomers of a molecule that exist in solution or in a cell. They are interchangeable forms because chemical bonds are rearranged many times spontaneously. This is different from chirality, where molecules are mirror images (or enantiomers) of each other. DFT method was carried out to study the tautomerization of the mechanism of carmustine as an anti-cancer drug. In the carmustine structure, two conformational tautomers were predicted and both two tautomer structures were demonstrated for considering the role of changing atoms in the conformation of carmustine. Relative energies obtained at the B3LYP/6-311G++ (d,p) , Aug-cc-pVDZ and 6-311++g(2d,2p) basis sets. The highest occupied molecular orbital (HOMO), The lowest unoccupied orbital (LUMO), and bandgap energy of structures were calculated. Electronics parameters were obtained. electrophilicity. Electronegativity, softness, and hardness for determining the reactivity of compounds in biological media. have been studied. According to the data, the structure of carmustine and two tautomer conformations are stable but T1 is more stable than the other one.