Identification of prolyl hydroxylation modifications in mammalian cell proteins

Prolyl hydroxylation is a PTM that plays an important role in the formation of collagen fibrils and in the oxygen‐dependent regulation of hypoxia inducible factor‐α (HIF‐α). While this modification has been well characterized in the context of these proteins, it remains unclear to what extent it occurs in the remaining mammalian proteome. We explored this question using MS to analyze cellular extracts subjected to various fractionation strategies. In one strategy, we employed the von Hippel Lindau tumor suppressor protein, which recognizes prolyl hydroxylated HIF‐α, as a scaffold for generating hydroxyproline capture reagents. We report novel sites of prolyl hydroxylation within five proteins: FK506‐binding protein 10, myosin heavy chain 10, hexokinase 2, pyruvate kinase, and C‐1 Tetrahydrofolate synthase. Furthermore, we show that identification of prolyl hydroxylation presents a significant technical challenge owing to widespread isobaric methionine oxidation, and that manual inspection of spectra of modified peptides in this context is critical for validation.     

Stability,oviposition attraction,and larvicidal activity of binary toxin from <Emphasis Type="Italic">Bacillus sphaericus</Emphasis> expressed in <Emphasis Type="Italic">Escherichia coli</Emphasis>

Bacillus sphaericus produces a two-chain binary toxin composed of BinA (42 kDa) and BinB (51 kDa), which are deposited as parasporal crystals during sporulation. The toxin is highly active against Culex larvae and Aedes and Anopheles mosquitoes, which are the principal vectors for the transmission of malaria, yellow fever, encephalitis, and dengue. The use of B. sphaericus and Bacillus thuringiensis in mosquito control programs is limited by their sedimentation in still water. In this study, the binA and binB genes were cloned and the recombinant BinAB protein was expressed in three strains of Escherichia coli. These recombinant strains were used in a toxicity assay against Culex quinquefasciatus larvae. The highest expression level was achieved when both proteins were expressed in a single operon construct. The BinAB protein expressed in the E. coli Arctic strain showed higher larvicidal activity than either of the recombinant proteins from the E. coli Ril or pLysS strains. Furthermore, it had the highest oviposition attraction (49.1%, P?相似文献   

Bottom-up regulation of bacterial growth in tropical phytotelm bromeliads

Evaluating the factors that regulate bacterial growth in natural ecosystems is a major goal of modern microbial ecology. Phytotelm bromeliads have been used as model ecosystems in aquatic ecology as they provide many independent replicates in a small area and often encompass a wide range of limnological conditions. However, as far as we know, there has been no attempt to evaluate the main regulatory factors of bacterial growth in these aquatic ecosystems. Here, we used field surveys to evaluate the main bottom-up factors that regulate bacterial growth in the accumulated water of tank bromeliads. Bacterial production, water temperature, water color, chlorophyll-a, and nutrient concentrations were determined for 147 different tank bromeliads in two different samplings. Bromeliad position and the season of sampling were also noted. Bacterial production was explained by ion ammonium concentration and water temperature, but the total variance explained was low (r ² = 0.104). Sampling period and bromeliad position were included in additional models that gave empirical support for predicting bacterial production. Bromeliad water tanks are extremely variable aquatic ecosystems in space (among bromeliads) and time (environmental conditions can change within hours), and it is well known that bacterial production responds rapidly to environmental change. Therefore, we concluded that several factors could independently regulate bacterial growth in phytotelm bromeliads depending on the characteristics of each bromeliad, such as location, amount of detritus, and ambient nutrient concentrations. A clear bottom-up limitation pattern of bacterial production in tropical phytotelm bromeliads was not found. Handling editor: Luigi Naselli-Flores     

New species of <Emphasis Type="Italic">Eugenia</Emphasis> sect. <Emphasis Type="Italic">Racemosae</Emphasis> (Myrtaceae) from Brazilian Amazon Rainforest

Summary  The new species Eugenia pallidopunctata, E. caducibracteata, E. tenuiflora and E. breviracemosa from the Brazilian Amazon, all belonging to Eugenia sect. Racemosae (Myrtaceae), are described, illustrated and compared with their putative close relatives. Data on the geographic distribution and habitat are given for the new taxa, as well as illustrations.     

Evaluation of the efficiency of the Coriolis air sampler for pollen detection in South Europe

The Coriolis δ air sampler is a new volumetric air sampler, dedicated to outdoor monitoring of airborne biological particles, including pollen and spores. In the present work, the performance of the Coriolis in the collection of pollen grains was evaluated in comparison with a Hirst spore trap, the most frequently used trap in aerobiological studies, in two cities of South Europe, Evora (Portugal) and Córdoba (Spain). Both concentration values are compared, and statistical analysis was carried out. The present study indicated that, in general, pollen counts for all taxa detected with the Hirst trap were higher than those detected with the Coriolis δ in both cities. In Córdoba, significant differences were detected for all taxa except for Cupressus, Olea and Pinus, while in Evora significant differences were noted for all except Pinus and Poaceae. Differences were particularly marked in species flowering during April and May. In spite of theses differences, Spearman correlation test results showed that the relationship between Hirst and Coriolis curves was always positive and significant (p > 0.01). Regards to the number of detected taxa, the results showed greater diversity for the Hirst sampler in both cities.     

Theoretical study on the molecular and electronic properties of some substances used for diabetes mellitus treatment

Diabetes mellitus (DM) is a disease that affects a large number of people, and the number of problems associated with the disease has been increasing in the past few decades. These problems include cardiovascular disorders, blindness and the eventual need to amputate limbs. Therefore, the quality of life for people living with DM is less than it is for healthy people. In several cases, metabolic syndrome (MS), which can be considered a disturbance of the lipid metabolism, is associated with DM. In this work, two drugs used to treat DM, pioglitazone and rosiglitazone, were studied using theoretical methods, and their molecular properties were related to the biological activity of these drugs. From the results, it was possible to correlate the properties of each substance – particularly electronic properties – with the biological interactions that are linked to their pharmacological effects. These results suggest that there are future prospects for designing or developing new drugs based on the correlation between theoretical and experimental properties.     

Molecular models of tryptophan synthase from Mycobacterium tuberculosis complexed with inhibitors

The development of new therapies against infectious diseases is vital in developing countries. Among infectious diseases, tuberculosis is considered the leading cause of death. A target for development of new drugs is the tryptophan pathway. The last enzyme of this pathway, tryptophan synthase (TRPS), is responsible for conversion of the indole 3-glycerol phosphate into indol and the condensation of this molecule with serine-producing tryptophan. The present work describes the molecular models of TRPS from Mycobacterium tuberculosis (MtTRPS) complexed with six inhibitors, the indole 3-propanol phosphate and five arylthioalkyl-phosphonated analogs of substrate of the alpha-subunit. The molecular models of MtTRPS present good stereochemistry, and the binding of the inhibitors is favorable. Thus, the generated models can be used in the design of more specific drugs against tuberculosis and other infectious diseases.