Search results for " stability."
showing 10 items of 1315 documents
A possible desensitized state conformation of the human α7 nicotinic receptor: A molecular dynamics study
2017
International audience; The determination of the conformational states corresponding to diverse functional roles of ligand gated ion channels is subject of intense investigation with various techniques, from X-rays structure determination to electrophysiology and computational modeling. Even with a certain number of structures becoming recently available, only few major structural features distinguishing conductive open channel from the non conductive resting protein have been highlighted, while high-resolution details are still missing. The characterization of the desensitized conformation(s) is even more complex, and only few specific characteristics have been identified. Furthermore, exp…
Characterization of sulfhydryl oxidase from Aspergillus tubingensis
2017
Background Despite of the presence of sulfhydryl oxidases (SOXs) in the secretomes of industrially relevant organisms and their many potential applications, only few of these enzymes have been biochemically characterized. In addition, basic functions of most of the SOX enzymes reported so far are not fully understood. In particular, the physiological role of secreted fungal SOXs is unclear. Results The recently identified SOX from Aspergillus tubingensis (AtSOX) was produced, purified and characterized in the present work. AtSOX had a pH optimum of 6.5, and showed a good pH stability retaining more than 80% of the initial activity in a pH range 4-8.5 within 20 h. More than 70% of the initia…
Biopreservation of Myoglobin in Crowded Environment: A Comparison between Gelatin and Trehalose Matrixes.
2017
Biopreservation by sugar and/or polymeric matrixes is a thoroughly studied research topic with wide technological relevance. Ternary amorphous systems containing both saccharides and proteins are extensively exploited to model the in vivo biopreservation process. With the aim of disentangling the effect of saccharides and polypeptidic crowders (such as gelatin) on the preservation of a model protein, we present here a combined differential scanning calorimetry and UV-vis spectrophotometry study on samples of myoglobin embedded in amorphous gelatin and trehalose + gelatin matrixes at different hydrations, and compare them with amorphous myoglobin-only and myoglobin-Trehalose samples. The res…
Physical Exercise and DNA Injury
2017
Regular, low-intensity physical activity is currently advocated for lowering the risk of developing many acute and especially chronic diseases. However, several lines of evidence attest that strenuous exercise may enhance inflammation and trigger the generation of free radical-mediated damage, thus overwhelming the undisputable benefits of regular, medium-intensity physical activity. Since reactive oxygen species are actively generated during high-intensity exercise, and these reactive compounds are known to impact DNA stability, we review here the current evidence about strenuous exercise and DNA injury. Despite the outcome of the various studies cannot be pooled due to considerable variat…
Penalized classification for optimal statistical selection of markers from high-throughput genotyping: application in sheep breeds
2018
The identification of individuals’ breed of origin has several practical applications in livestock and is useful in different biological contexts such as conservation genetics, breeding and authentication of animal products. In this paper, penalized multinomial regression was applied to identify the minimum number of single nucleotide polymorphisms (SNPs) from high-throughput genotyping data for individual assignment to dairy sheep breeds reared in Sicily. The combined use of penalized multinomial regression and stability selection reduced the number of SNPs required to 48. A final validation step on an independent population was carried out obtaining 100% correctly classified individuals. …
Development of a method to determine axitinib, lapatinib and afatinib in plasma by micellar liquid chromatography and validation by the European Medi…
2017
A method based on micellar liquid chromatography to quantify the tyrosine kinase inhibitors axitinib, lapatinib and afatinib in plasma is reported. The sample pretreatment was a simple 1/5-dilution in a pure micellar solution, filtration and direct injection, without requiring extraction or purification steps. The three drugs were resolved from the matrix in 17 min, using an aqueous solution of 0.07 M sodium dodecyl sulfate – 6.0% 1-pentanol, buffered at pH 7 with 0.01 M phosphate salt as mobile phase, running under isocratic mode at 1 mL/min through a C18 column. The detection was performed by absorbance at 260 nm. An accurate mathematical relationship was established between the retention…
Stability of OBPs
2020
Odorant binding proteins (OBPs) are small proteins, some of which bind odorants with high specificity. OBPs are relatively easy to produce and show a pronounced stability toward thermal and chemical denaturation. This high stability renders OBPs attractive candidates for the development of odorant detections systems. Unfortunately, binding of odorants is not easy to quantify due to lack of spectroscopic signals upon binding. Therefore, a possible approach to detect binding is to employ the shift in thermal or chemical stability upon ligand-protein interaction. Being a rather indirect approach, the experimental setup should be done with care. Here, the experimental results on stability of OB…
DNA folds threaten genetic stability and can be leveraged for chemotherapy
2020
International audience; Damaging DNA is a current and efficient strategy to fight against cancer cell proliferation. Numerous mechanisms exist to counteract DNA damage, collectively referred to as the DNA damage response (DDR) and which are commonly dysregulated in cancer cells. Precise knowledge of these mechanisms is necessary to optimise chemotherapeutic DNA targeting. New research on DDR has uncovered a series of promising therapeutic targets, proteins and nucleic acids, with application notably via an approach referred to as combination therapy or combinatorial synthetic lethality. In this review, we summarise the cornerstone discoveries which gave way to the DNA being considered as an…
Effect of iron chelates on oil–water interface, stabilized by milk proteins: The role of phosphate groups and pH. Prediction of iron transfer from aq…
2010
International audience; Iron incorporated into food systems induces oxidation and precipitation. The consequences are reduced bioavailability and a functional modification of other food components such as proteins. The iron-chelates such as ferrous bisglycinate represent a possibility to avoid side effects, since the iron is protected. The aim of this study is to investigate the effects of iron-chelates compounds on the properties of an oil/water interface stabilized by caseinate or β-lacotoglobulin, under environmental conditions at 20 °C. Analyses were performed using dynamic drop tensiometry during 5000 s. The aqueous bulk phase is an imidazole/acetate buffer (0.1 M), containing 0.4 × 10…
Balance Perturbations as a Measurement Tool for Trunk Impairment in Cross-Country Sit Skiing
2018
In cross-country sit-skiing, the trunk plays a crucial role in propulsion generation and balance maintenance. Trunk stability is evaluated by automatic responses to unpredictable perturbations; however, electromyography is challenging. The aim of this study was to identify a measure to group sit-skiers according to their ability to control the trunk. Seated in their competitive sit-ski, 10 male and 5 female Paralympic sit-skiers received 6 forward and 6 backward unpredictable perturbations in random order. k-means clustered trunk position at rest, delay to invert the trunk motion, and trunk range of motion significantly into 2 groups. In conclusion, unpredictable perturbations might quantif…