Evaluation of chalcones as inhibitors of glutathione S‐transferase

Glutathione S‐transferases (GSTs) are the superfamily of multifunctional detoxification isoenzymes and play an important role in cellular signaling. In the present study, potential inhibition effects of chalcones were tested against human GST. For this purpose, GST was purified from human erythrocytes with 5.381 EU?mg^?1 specific activity and 51.95% yield using a GSH–agarose affinity chromatographic method. The effects of chalcones on in vitro GST activity were tested at various concentrations. K_i constants of chalcones were found in the range of 7.76–41.93 μM. According to the results, 4‐fluorochalcone showed a better inhibitory effect compared with the other compounds. The inhibition mechanisms of 2'‐hydroxy‐4‐methoxychalcone and 4‐methoxychalcone were noncompetitive, whereas the inhibition mechanisms of 4'‐ hydroxychalcone, 4‐ fluorochalcone, and 4,4'‐ diflurochalcone were competitive.     

High-Density Proximity Mapping Reveals the Subcellular Organization of mRNA-Associated Granules and Bodies

1. Download high-res image (224KB)
2. Download full-size image

     

Residue packing in globular and intrinsically disordered proteins

Intrinsically disordered proteins (IDPs)/regions do not have well‐defined secondary and tertiary structures, however, they are functional and it is critical to gain a deep understanding of their residue packing. The shape distributions methodology, which is usually utilized in pattern recognition, clustering, and classification studies in computer science, may be adopted to study the residue packing of the proteins. In this study, shape distributions of the globular proteins and IDPs were obtained to shed light on the residue packing of their structures. The shape feature that was used is the sphericity of tetrahedra obtained by Delaunay Tessellation of points of Cα coordinates. Then the sphericity probability distributions were compared by using Principal Component Analysis. This computational structural study shows that the set of IDPs constitute a more diverse set than the set of globular proteins in terms of the geometrical properties of their network structures.     

Fatty acid and tocochromanol patterns of some Turkish Boraginaceae—a chemotaxonomic approach

The plant family Boraginaceae is known to produce a set of unusual fatty acids in the seed oils. In this study, the fatty acid, tocopherol, tocotrienol and plasto-chromanol-8 contents of some Onosma species ( Onosma sericeum, O. armeniacum and O. polioxanthum ) all belonging to sect. Onosma, Anchusa leptophylla subsp. leptophylla, Alkanna froedini and Paracaryum stenophyllum were determined. Some of the studied species are endemic for Turkey. While oleic, linoleic and alpha linolenic acid are the highest as usual fatty acids, gamma linolenic and stearidonic acids are more variable unusual fatty acids in studied genera patterns and the relative concentrations some of these fatty acids and partly also the tocochromanols in Boraginaceae seed oils are suggested to have chemotaxonomic value in this family. In particular, the presence or absence of chain elongation to erucic acid (22:1) and the presence or absence of Δ6-methylene-interrupted polyenoic acids such as γ-linolenic and stearidonic acid are determined and marked as indicators of taxonomic relationship.     

In vitro culture of tobacco protoplasts: Use of feeder techniques to support division of cells plated at low densities

Summary Tobacco protoplasts obtained from leaf mesophyll cells and suspended in agar nutrient medium divided and produced colonies only when plated at high densities, above 10⁴ cells per ml. At such densities coalescence of the expanding colonies occurred at high frequency. Nondividing X-irradiated protoplasts used as feeder cells supported division of viable protoplasts plated at densities as low as 10² cells per ml. The feeder cell technique should thus facilitate the application of screening procedures for the isolation of colonies originating from single mutated cells occurring in a suspended population.     

A Raman-spectroscopy-based approach for detection and discrimination of <Emphasis Type="Italic">Streptococcus thermophilus</Emphasis> and <Emphasis Type="Italic">Lactobacillus bulgaricus</Emphasis> phages at low titer in raw milk

In this study, a method combining Raman spectroscopy with chemometric analysis was developed for detection of phage presence in raw milk and discrimination of Streptococcus thermophilus and Lactobacillus bulgaricus phages which are among the main phages causing problems in dairy industry. For this purpose, S. thermophilus and L. bulgaricus phages were added into raw milk separately, and then some pretreatments such as fat separation, removal of casein, and filtration were applied to the raw milk samples. Raman spectra of the samples were collected and then analyzed using principal component analysis in order to discriminate these phages in raw milk. In the next step, dilutions of S. thermophilus phages in pretreated raw milk were prepared, and Raman spectra were collected. These spectra were analyzed by using partial least squares method to quantify phages in low titer. Consequently, it has been demonstrated that S. thermophilus and L. bulgaricus phages, which have titers sufficient to fail the fermentation (~?10⁷ pfu/mL) and have lower titers (10²–10³ pfu/mL), could be discriminated from antibiotic and each other. Additionally, low concentrations of S. thermophilus phages (10² pfu/mL) could be detected through Raman spectroscopy with a short analysis time (60 min) and high coefficient of determination (R²) values for both calibration (0.985) and validation (0.906) with a root mean square error of calibration of 70.54 and root mean square error of prediction of 165.47. However, a lower success was achieved with L. bulgaricus phages and the obtained coefficient of determination values were not sufficiently high (0.649).     

Squalius semae,a new species of chub from the Euphrates River,Eastern Anatolia (Teleostei: Cyprinidae)

In a study of the fishes of the Euphrates River (Persian Gulf basin) three species of Squalius belonging to the cephalus-group were found: The Tohma population was identified as S. seyhanensis and the Merzimen and Hilvan populations as S. berak. The comparison of 28 metric and 5 meristic parameters and morphological characters showed that the populations of the northern Euphrates River drainages are distinct and belong to a hitherto unnamed species. We describe it here as Squalius semae sp. n.

http://www.zoobank.org/urn:lsid:zoobank.org:pub:D195B69C-C6CB-4DEB-B85D-5B695F917CE5     

Caryological study on four Hesperis L. (Cruciferae) taxa from the Diaplictos (Dvorák) Dvorák section in Turkey

This study examined chromosome numbers and karyotypes of four taxa, Hesperis novakii Dvorák, H. bottae Fourn., H. balansae Fourn. and H. syriaca (DC.) Dvorák, from naturally growing Diaplictos (Dvorák) Dvorák section, which is represented by only these four taxa in Turkey, in the genus Hesperis. H. novakii and H. syriaca have 2n=14 chromosomes, H. bottae and H. balansae have 2n=12 chromosomes in somatic cells. Total chromosome lengths are 5.37 mum and 2.17 mum in H. novakii, 5.38 mum and 2.70 mum in H. bottae, 9.59 mum and 4.28 mum in H. balansae, 4.88 mum and 2.32 mum in H. syriaca (no. 4969), 7.89 mum and 3.44 mum in H. syriaca (no. 4971). The karyotypes are as follows: H. novakii consists of 3m+1sm+1st+2T, H. bottae consists of 4m+2st, H. balansae consists of 4m+2sm, H. syriaca (no. 4969) consists of 3m+1sm+1st+2T and H. syriaca (no. 4971) consists of 3m+1sm+1st+2T chromosome pairs. Results were discussed from a cytological and taxonomical point of view.     

Exome sequences and multi‐environment field trials elucidate the genetic basis of adaptation in barley

Broadening the genetic base of crops is crucial for developing varieties to respond to global agricultural challenges such as climate change. Here, we analysed a diverse panel of 371 domesticated lines of the model crop barley to explore the genetics of crop adaptation. We first collected exome sequence data and phenotypes of key life history traits from contrasting multi‐environment common garden trials. Then we applied refined statistical methods, including some based on exomic haplotype states, for genotype‐by‐environment (G×E) modelling. Sub‐populations defined from exomic profiles were coincident with barley's biology, geography and history, and explained a high proportion of trial phenotypic variance. Clear G×E interactions indicated adaptation profiles that varied for landraces and cultivars. Exploration of circadian clock‐related genes, associated with the environmentally adaptive days to heading trait (crucial for the crop's spread from the Fertile Crescent), illustrated complexities in G×E effect directions, and the importance of latitudinally based genic context in the expression of large‐effect alleles. Our analysis supports a gene‐level scientific understanding of crop adaption and leads to practical opportunities for crop improvement, allowing the prioritisation of genomic regions and particular sets of lines for breeding efforts seeking to cope with climate change and other stresses.