Recombinant Expression of a Plant-Derived Dimeric Antifungal Peptide (DiSkh-AMP1) Joined by a Flexible Linker in Escherichia coli and Evaluation of Its Biological Activity In Vitro

International Journal of Peptide Research and Therapeutics - DiSkh-AMP1, a novel dimeric antifungal peptide contained 65 amino acid residues was recombinant produced by a flexible linker to improve...     

Tissue engineering; strategies,tissues, and biomaterials

Current tissue regenerative strategies rely mainly on tissue repair by transplantation of the synthetic/natural implants. However, limitations of the existing strategies have increased the demand for tissue engineering approaches. Appropriate cell source, effective cell modification, and proper supportive matrices are three bases of tissue engineering. Selection of appropriate methods for cell stimulation, scaffold synthesis, and tissue transplantation play a definitive role in successful tissue engineering. Although the variety of the players are available, but proper combination and functional synergism determine the practical efficacy. Hence, in this review, a comprehensive view of tissue engineering and its different aspects are investigated.     

Overexpression of recombinant Nep1 in Escherichia coli and its use as a biological agent for control of Sinapis arvensis

Weeds are a significant part of the pests limiting crop production. Currently, chemical herbicides are widely used for weed control. Environment pollution and the rise of resistant strains highlight the need for new herbicides. Nep1 is a natural bio-herbicide protein which is an effective necrosis stimulant in dicotyledonous weeds. In this study, the cDNA encoding nep1 was isolated form Fusarium oxysporum, cloned and overexpressed in Escherichia coli. The Nep1 inclusion body was purified and refolded. For biological assay, the recombinant Nep1 was applied on Sinapis arvensis, as a chemical herbicide-resistant weed, and on Nicotiana tabacum, as a model plant. Our results show a significant necrosis on the leaves of S. arvensis and N. tabacum after spraying 50 μg/ml of the recombinant protein.     

Enterotoxin B Anchored Exosome Induces Endoplasmic Reticulum Mediated Apoptosis in the Breast Cancer Cell Line

Exosomes (EXOs) are nanovesicles secreted by all cell types, which can be used as an acellular strategy for cancer immunotherapy. Application of superantigens (SAgs) as an adjuvant enhances the immune responses created by EXOs. In addition, it is reported that the combination of SAgs with EXOs derived from cancer cells causes the induction of mitochondrial apoptosis. In the current study, we aimed to analysis the effect of EXOs with or without SAg on the endoplasmic reticulum (ER) mediated apoptosis. We anchored staphylococcal enterotoxin B (SEB) on EXOs isolated from a triple negative breast cancer cell line (EXO/SEB). Then, to identify the impact of EXO/SEB on the induction of ER apoptosis, MDA MB-231 cell line was treated with 25, 50 and 100 μg/ml EXO/SEB, EXO and SEB for 24 h and the expression ratio of GRP-78, CHOP and IRE-1 was assessed using real-time PCR and the fold change expression was assessed by Rest 2009. Exposing the cells to 100 μg/ml EXOs and 25 μg/ml EXO/SEB remarkably increased GRP-78 expression (p?<?0.001). Furthermore, the ratio of CHOP expression was considerably raised after treatment with 50 and 100 μg/ml EXO/SEB (p?<?0.001). On the other hand, our observation demonstrated a significant increase in the IRE-1 expression ratio at the concentration of 25, 50 and 100 μg/ml of EXO/SEB (21.99, 13.1 and 9.82 fold) (p?<?0.001). We concluded that EXO/SEB is able to induce ER mediated apoptosis via increased expression of CHOP and IRE-1 genes.     

Synthesis and preliminary biological evaluation of [11C]methyl (2-amino-5-(benzylthio)thiazolo[4,5-d]pyrimidin-7-yl)-d-leucinate for the fractalkine receptor (CX3CR1)

The reference standard methyl (2-amino-5-(benzylthio)thiazolo[4,5-d]pyrimidin-7-yl)-d-leucinate (5) and its precursor 2-amino-5-(benzylthio)thiazolo[4,5-d]pyrimidin-7-yl)-d-leucine (6) were synthesized from 6-amino-2-mercaptopyrimidin-4-ol and BnBr with overall chemical yield 7% in five steps and 4% in six steps, respectively. The target tracer [¹¹C]methyl (2-amino-5-(benzylthio)thiazolo[4,5-d]pyrimidin-7-yl)-d-leucinate ([¹¹C]5) was prepared from the acid precursor with [¹¹C]CH₃OTf through O-[¹¹C]methylation and isolated by HPLC combined with SPE in 40–50% radiochemical yield, based on [¹¹C]CO₂ and decay corrected to end of bombardment (EOB). The radiochemical purity was >99%, and the specific activity (SA) at EOB was 370–1110 GBq/μmol with a total synthesis time of ～40-min from EOB. The radioligand depletion experiment of [¹¹C]5 did not display specific binding to CX₃CR1, and the competitive binding assay of ligand 5 found much lower CX₃CR1 binding affinity.     

Bioinformatics Predictions,Expression, Purification and Structural Analysis of the PE38KDEL-scfv Immunotoxin Against EPHA2 Receptor

International Journal of Peptide Research and Therapeutics - Various strategies have been proposed for treatment of cancer, including common therapies such as surgery, chemotherapy, radiation...     

Enhancement of biosurfactants and biofilm production after gamma irradiation-induced mutagenesis of Bacillus subtilis UTB1, a biocontrol agent of Aspergillus flavus

Bacillus subtilis UTB1 is known as a biocontrol agent of Aspergillus flavus in pistachio nuts. In order to reduce growth of this fungal pathogen to a greater extent, a random mutagenesis using gamma irradiation was applied in strain UTB1. We studied the effects of different doses of irradiation (from 100 Gray to 3000 Gray) and efficiency of 500 selected colonies was assessed against A. flavus in a plate assay. Forty-five colonies exhibited higher inhibition activity compared to the non-irradiated wild type. Eight mutants out of the 45 were selected based on different polymorphism patterns obtained by rep-PCR (ERIC and BOX). Six mutants demonstrated enhanced production of biosurfactants on blood agar medium and in oil spreading technique and they also revealed more robust biofilm in comparison with the wild type UTB1. These observations showed that the six mutants are more effective biocontrol agents than the parental strain, suggesting that they would be promising biocontrol candidates against A. flavus in pistachio nuts.     

Genome-scale metabolic model-based engineering of Escherichia coli enhances recombinant single-chain antibody fragment production

Biotechnology Letters - Escherichia coli is an attractive and cost-effective cell factory for producing recombinant proteins such as single-chain variable fragments (scFvs). AntiEpEX-scFv is a...     

Detection of Anti-tetanus Toxoid Monoclonal Antibody by Using Modified Polycarbonate Surface

In recent years, CD surface modification methods are employed for immunoassay techniques that is called BioCD technology. In this research, first polycarbonate surface was activated with UV ozone and a hydrophilic surface was obtained. Contact angle measurements and atomic force microscopy technique confirmed the hydrophilic property of surface. After that, tetanus toxoid was immobilized on modified CD surface then specific monoclonal antibody, gold nanoparticles conjugated antibody, silver salt, and hydroquinone were added on modified CD surface. So a sandwiches complex as tetanus toxoid, tetanus toxoid monoclonal antibody, and gold nanoparticles conjugated antibody was obtained on CD surface. ATR result showed the immobilization of tetanus toxoid on modified CD surface. Localized surface plasmon resonance (LSPR) and DLS results confirmed the complex formation. Silver salt and hydroquinone were added for signal amplification. Detection limit of anti-tetanus toxoid IgG monoclonal antibody was obtained 0.005 IU/ml by LSPR and DLS techniques. The presented method increases the assay’s sensitivity. BioCD-based immunoassay for detection of anti-tetanus toxoid IgG monoclonal antibody could be applicable in development and fabrication of biomedical devices.     

A novel class of positive allosteric modulators of AMPA receptors: design, synthesis, and structure-activity relationships of 3-biphenyl-4-yl-4-cyano-5-ethyl-1-methyl-1H-pyrrole-2-carboxylic acid, LY2059346

The synthesis and structure-activity relationship (SAR) of novel and highly potent positive allosteric modulators of AMPA receptors, 3-biphenyl-4-yl-4-cyano-5-ethyl-1-methyl-1H-pyrrole-2-carboxylic acid, are described. These studies indicated that higher potency was achieved with ortho substitution of the distal (D) phenyl of the 3-biphenyl ring and resulted in the discovery of a potent pyrrole LY2059346 (23q), that was selected for further evaluation in in vitro native tissue assays and in vivo experiments.