The nucleobase-cation-symport-1 (NCS1) transporters are essential components of salvage pathways for nucleobases and related metabolites. Here, we report the 2.85-angstrom resolution structure of the NCS1 benzyl-hydantoin transporter, Mhp1, from Microbacterium liquefaciens. Mhp1 contains 12 transmembrane helices, 10 of which are arranged in two inverted repeats of five helices. The structures of the outward-facing open and substrate-bound occluded conformations were solved, showing how the outward-facing cavity closes upon binding of substrate. Comparisons with the leucine transporter LeuT(Aa) and the galactose transporter vSGLT reveal that the outward- and inward-facing cavities are symmetrically arranged on opposite sides of the membrane. The reciprocal opening and closing of these cavities is synchronized by the inverted repeat helices 3 and 8, providing the structural basis of the alternating access model for membrane transport.

Drug efflux proteins are widespread amongst microorganisms, including pathogens. They can contribute to both natural insensitivity to antibiotics and to emerging antibiotic resistance and so are potential targets for the development of new antibacterial drugs. The design of such drugs would be greatly facilitated by knowledge of the structures of these transport proteins, which are poorly understood, because of the difficulties of obtaining crystals of quality. We describe a structural genomics approach for the amplified expression, purification and characterisation of prokaryotic drug efflux proteins of the 'Major Facilitator Superfamily' (MFS) of transport proteins from Helicobacter pylori, Staphylococcus aureus, Escherichia coli, Enterococcus faecalis, Bacillus subtilis, Brucella melitensis, Campylobacter jejuni, Neisseria meningitides and Streptomyces coelicolor. The H. pylori putative drug resistance protein, HP1092, and the S. aureus QacA proteins are used as detailed examples. This strategy is an important step towards reproducible production of transport proteins for the screening of drug binding and for optimisation of crystallisation conditions to enable subsequent structure determination.

Summaryg-Glutamyltranspeptidase (GGT) is a periplasmic enzyme of Helicobacter pylori implicated in its pathogenesis towards mammalian cells. We have cloned and expressed the H. pylori strain 26695 recombinant GGT protein in Escherichia coli and purified it to homogeneity. The purified protein exhibited hydrolysis activity with very high affinities for glutamine and glutathione shown by apparent K m values lower than 1 mM. H. pylori cells were unable to take up extracellular glutamine and glutathione directly. Instead, these substances were hydrolysed to glutamate by the action of GGT outside the cells. The glutamate produced was then transported by a Na + -dependent reaction into H. pylori cells, where it was mainly incorporated into the TCA cycle and partially utilized as a substrate for glutamine synthesis. These observations show that one of the principle physiological functions of H. pylori GGT is to enable H. pylori cells to utilize extracellular glutamine and glutathione as a source of glutamate. As glutamine and glutathione are important nutrients for maintenance of healthy gastrointestinal tissue, their depletion by the GGT enzyme is hypothesized to account for the damaging of mammalian cells and the pathophysiology of H. pylori.

Pre-conditioning of MSCs with ATRA increased efficacy of cell therapy by activation of survival signalling pathways, trophic factors and release of pro-angiogenic molecules.

This article provides a brief overview of DNA vaccines. First, the basic DNA vaccine design strategies are described, then specific issues related to the industrial production of DNA vaccines are discussed, including the production and purification of DNA products such as plasmid DNA, minicircle DNA, minimalistic, immunologically defined gene expression (MIDGE) and Doggybone™. The use of adjuvants to enhance the immunogenicity of DNA vaccines is then discussed. In addition, different delivery routes and several physical and chemical methods to increase the efficacy of DNA delivery into cells are explained. Recent preclinical and clinical trials of DNA vaccines for COVID-19 are then summarized. Lastly, the advantages and obstacles of DNA vaccines are discussed.

Recently, special attention has been paid to marine origin compounds such as carbohydrates, peptides, lipids, and carotenoids, which are extracted from microalgae and have anticancer, anti-inflammatory, antimicrobial (e.g., anti-COVID-19 activity), and antioxidant properties in biomedicine and pharmaceutical biotechnology. In addition, these photosynthetic marine microorganisms have several applications in biotechnology and are suitable hosts for the production of recombinant proteins/peptides, such as monoclonal antibodies and vaccines. Silica-based nanoparticles obtained from diatoms (a microalgae group) are used as drug delivery carriers owing to their biodegradability, easy functionalization, low cost, and simple features compared to synthetics, which make these agents proper alternatives for synthetic silica nanoparticles. Therefore, diatom-based nanoparticles are a viable option for the delivery of anti-cancer drugs and reducing the side-effects of cancer chemotherapy.

Incidence of diabetes mellitus is dramatically growing in the world. Oxidative stress, advanced glycation end products (AGEs) and receptor for AGE (RAGE) play key role in the pathogenesis of diabetes. Little is known about resveratrol effects on the liver. We hypothesize that resveratrol may exert a hepatoprotective effect in diabetic rats. Male rats with diabetes were treated with or without resveratrol at 1, 5 and 10 mg/kg body weight for 30 days. Total AGEs and malondialdehyde (MDA) levels in liver tissues were determined by spectrofluorimetric methods. Total antioxidant capacity and total oxidant contents in the liver and glucose in plasma were measured by a colorimetric assay. Expression of RAGE was assayed in liver of all animals using quantitative polymerase chain reaction. In liver tissue extract of resveratrol-treated rats with diabetes, MDA levels, total oxidant, plasma glucose and expression of RAGE were significantly reduced compared to the untreated group. Moreover, total antioxidant levels were significantly increased in treated rats. There was no significant difference in AGE contents among all groups. These results revealed that resveratrol had beneficial effects on the liver by extenuating oxidative stress and down regulation of RAGE expression.

our findings revealed a major role of resveratrol in apoptosis, invasion, and switching of EMT to MET phenotype through upregulation of miR-200c in CRC. J. Cell. Biochem. 118: 1547-1555, 2017. © 2016 Wiley Periodicals, Inc.