Effects of temperature, aurintricarboxylic acid and cibacron blue on 2',5'-oligoadenylate binding protein (RNase L) activity in rabbit reticulocyte lysates

The binding of p3A4,3'-32P [pCp] to rabbit reticulocyte RNase L can be displaced by the trimer and tetramer triphosphates of 2',5'-oligoadenylates (2-5A). Using assay conditions of protein synthesis, 2-5A trimer or tetramer triphosphates are shown to be equally effective when the displacement is done at 4 degrees C (on ice). In contrast, at 30 degrees C, the tetramer triphosphates still displace whereas the trimer triphosphates become ineffective. When lysates are preincubated at temperature ranging from 4 degrees-37 degrees C, the same results are obtained even when the subsequent displacement is done on ice. Incubation temperature also significantly affects the ability of metabolically stable dyes cibacron blue and aurintricarboxylic acid to inhibit RNase L binding activity. Taken together, these results suggest that rabbit reticulocyte RNase L may assume multiple conformations which are differentially affected by various forms of 2-5A or other compounds.     

Crystal Structure of Manganese Lipoxygenase of the Rice Blast Fungus Magnaporthe oryzae

Lipoxygenases (LOX) are non-heme metal enzymes, which oxidize polyunsaturated fatty acids to hydroperoxides. All LOX belong to the same gene family, and they are widely distributed. LOX of animals, plants, and prokaryotes contain iron as the catalytic metal, whereas fungi express LOX with iron or with manganese. Little is known about metal selection by LOX and the adjustment of the redox potentials of their protein-bound catalytic metals. Thirteen three-dimensional structures of animal, plant, and prokaryotic FeLOX are available, but none of MnLOX. The MnLOX of the most important plant pathogen, the rice blast fungus Magnaporthe oryzae (Mo), was expressed in Pichia pastoris. Mo-MnLOX was deglycosylated, purified to homogeneity, and subjected to crystal screening and x-ray diffraction. The structure was solved by sulfur and manganese single wavelength anomalous dispersion to a resolution of 2.0 Å. The manganese coordinating sphere is similar to iron ligands of coral 8R-LOX and soybean LOX-1 but is not overlapping. The Asn-473 is positioned on a short loop (Asn-Gln-Gly-Glu-Pro) instead of an α-helix and forms hydrogen bonds with Gln-281. Comparison with FeLOX suggests that Phe-332 and Phe-525 might contribute to the unique suprafacial hydrogen abstraction and oxygenation mechanism of Mo-MnLOX by controlling oxygen access to the pentadiene radical. Modeling suggests that Arg-525 is positioned close to Arg-182 of 8R-LOX, and both residues likely tether the carboxylate group of the substrate. An oxygen channel could not be identified. We conclude that Mo-MnLOX illustrates a partly unique variation of the structural theme of FeLOX.     

The association between low-carbohydrate diet score and sleep duration among Iranian adults

Sleep and Biological Rhythms - Sleep disorders are linked to obesity, type 2 diabetes mellitus (T2DM) and cardiovascular disease (CVD). The evidence suggests that dietary carbohydrate content may...     

Gastrointestinal nematodes of wild sheep (Ovis orientalis) from Iran.

A total of 250 wild sheep (Ovis orientalis) from different national parks and protected regions of Iran were examined for gastrointestinal nematodes at necropsy. Twenty five species of nematodes were found. Marshallagia marshalli, Ostertagia spp; Nematodirus spp; and Skrjabinema ovis were the most prevalent. Although all the species found are recorded from wild sheep for the first time in Iran, 88% were reported previously from domestic sheep. New host and distribution records for Nematodirus davtiani, N. gazellae and Nematodirella longissimespiculata were established during the present study.     

Neuropathological and genomic characterization of glioblastoma-induced rat model: How similar is it to humans for targeted therapy?

Glioblastoma multiforme (GBM) is a unique aggressive tumor and mostly develops in the brain, while rarely spreading out of the central nervous system. It is associated with a high mortality rate; despite tremendous efforts having been made for effective therapy, tumor recurrence occurs with high prevalence. To elucidate the mechanisms that lead to new drug discovery, animal models of tumor progression is one of the oldest and most beneficial approaches to not only investigating the aggressive nature of the tumor, but also improving preclinical research. It is also a useful tool for predicting novel therapies' effectiveness as well as side effects. However, there are concerns that must be considered, such as the heterogeneity of tumor, biological properties, pharma dynamic, and anatomic shapes of the models, which have to be similar to humans as much as possible. Although several methods and various species have been used for this approach, the real recapitulation of the human tumor has been left under discussion. The GBM model, which has been verified in this study, has been established by using the Rat C6 cell line. By exploiting bioinformatic tools, the similarities between aberrant gene expression and pathways have been predicted. In this regard, 610 common genes and a number of pathways have been detected. Moreover, while magnetic resonance imaging analysis enables us to compare tumor features between these two specious, pathological findings provides most of the human GBM characteristics. Therefore, the present study provides genomics, pathologic, and imaging evidence for showing the similarities between human and rat GBM models.     

A Meta-Analysis of the Prevalence of Toxoplasmosis in Livestock and Poultry Worldwide

EcoHealth - Toxoplasma gondii causes toxoplasmosis with a global prevalence in the world. A large proportion of human illness is most frequently associated with consuming raw and undercooked meat...