Search results for "PEPTIDE"
showing 10 items of 4589 documents
The Nonbilayer Lipid MGDG and the Major Light-Harvesting Complex (LHCII) Promote Membrane Stacking in Supported Lipid Bilayers.
2018
The thylakoid membrane of algae and land plants is characterized by its intricate architecture, comprising tightly appressed membrane stacks termed grana. The contributions of individual components to grana stack formation are not yet fully elucidated. As an in vitro model, we use supported lipid bilayers made of thylakoid lipid mixtures to study the effect of major light-harvesting complex (LHCII), different lipids, and ions on membrane stacking, seen as elevated structures forming on top of the planar membrane surface in the presence of LHCII protein. These structures were examined by confocal laser scanning microscopy, atomic force microscopy, and fluorescence recovery after photobleachi…
Phosphinotripeptidic Inhibitors of Leucylaminopeptidases
2021
Phosphinate pseudopeptide are analogs of peptides containing phosphinate moiety in a place of the amide bond. Due to this, the organophosphorus fragment resembles the tetrahedral transition state of the amide bond hydrolysis. Additionally, it is also capable of coordinating metal ions, for example, zinc or magnesium ions. These two properties of phosphinate pseudopeptides make them an ideal candidate for metal-related protease inhibitors. This research investigates the influence of additional residue in the P2 position on the inhibitory properties of phosphinopeptides. The synthetic strategy is proposed, based on retrosynthetic analysis. The N-C-P bond formation in the desired compounds is …
X!TandemPipeline: a tool to manage sequence redundancy for protein inference and phosphosite identification
2017
X!TandemPipeline is a software designed to perform protein inference and to manage redundancy in the results of phosphosite identification by database search. It provides the minimal list of proteins or phosphosites that are present in a set of samples using grouping algorithms based on the principle of parsimony. Regarding proteins, a two-level classification is performed, where groups gather proteins sharing at least one peptide and subgroups gather proteins that are not distinguishable according to the identified peptides. Regarding phosphosites, an innovative approach based on the concept of phosphoisland is used to gather overlapping phosphopeptides. The graphical interface of X!Tandem…
Ammonium acts systemically while nitrate exerts an additional local effect on Medicago truncatula nodules
2020
National audience; Symbiotic nitrogen fixation (SNF) has a high energetic cost for legume plants; legumes thus reduce SNF when soil N is available. The present study aimed to increase our understanding regarding the impacts of the two principal forms of available N in soils (ammonium and nitrate) on SNF. We continuously measured the SNF of Medicago truncatula under controlled conditions. This permitted nodule sampling for comparative transcriptome profiling at points connected to the nodules' reaction following ammonium or nitrate applications. The N component of both ions systemically induced a rhythmic pattern of SNF, while the activity in control plants remained constant. This rhythmic a…
Proteomic insights into the immune response of the Colorado potato beetle larvae challenged with Bacillus thuringiensis.
2019
Bacillus thuringiensis (Bt) toxins constitute effective, environmentally safe biopesticides. Nevertheless, insects' tolerance to Bt is influenced by environmental factors affecting immunity. To understand larval immune response in the devastating coleopteran insect pest Colorado potato beetle (CPB), we undertook a proteomic analysis of hemolymph of non-treated control larvae and larvae consuming non-lethal doses of spore-crystal mixtures containing the coleopteran-active Cry3Aa toxin. Results revealed lower amount of proteins involved in insect growth and higher amount of immune response-related proteins in challenged insects, sustaining the larval weight loss observed. Additionally, we fou…
Boolean computation in plants using post-translational genetic control and a visual output signal
2018
[EN] Due to autotrophic growing capacity and extremely rich secondary metabolism, plants should be preferred targets of synthetic biology. However, developments in plants usually run below those in other taxonomic groups. In this work we engineered genetic circuits capable of logic YES, OR and AND Boolean computation in plant tissues with a visual output signal. The circuits, which are deployed by means of Agrobacterium tumefaciens, perform with the conditional activity of the MYB transcription factor Roseal from Antirrhinum majus inducing the accumulation of anthocyanins, plant endogenous pigments that are directly visible to the naked eye or accurately quantifiable by spectrophotometric a…
The Pseudomonas fluorescens Siderophore Pyoverdine Weakens Arabidopsis thaliana Defense in Favor of Growth in Iron-Deficient Conditions
2016
SPE EA BIOME IPM UB INRA; International audience; Pyoverdines are siderophores synthesized by fluorescent Pseudomonas spp. Under iron-limiting conditions, these high-affinity ferric iron chelators are excreted by bacteria in the soil to acquire iron. Pyoverdines produced by beneficial Pseudomonas spp. ameliorate plant growth. Here, we investigate the physiological incidence and mode of action of pyoverdine from Pseudomonas fluorescens C7R12 on Arabidopsis (Arabidopsis thaliana) plants grown under iron-sufficient or iron-deficient conditions. Pyoverdine was provided to the medium in its iron-free structure (apo-pyoverdine), thus mimicking a situation in which it is produced by bacteria. Rema…
Enhancing heterologous protein expression and secretion in HEK293 cells by means of combination of CMV promoter and IFNα2 signal peptide
2016
Efficient production and secretion of recombinant proteins in mammalian cell lines relies in a combination of genetic, metabolic and culture strategy factors. The present work assesses the influence of two key genetic components of expression vectors (promoter and signal peptide) on protein production and secretion effciency in HEK293 cells expressing eGFP as a reporter protein. Firstly, the strength of 3 different promoters was evaluated using transient expression methods. Flow cytometry analysis revealed that the highest level of intracellular protein expression was found when eGFP was under the control of CMV promoter, being 3-times higher in comparison to the rest of the promoters teste…
Marine Cryptophytes Are Great Sources of EPA and DHA
2017
Microalgae have the ability to synthetize many compounds, some of which have been recognized as a source of functional ingredients for nutraceuticals with positive health effects. One well-known example is the long-chain polyunsaturated fatty acids (PUFAs), which are essential for human nutrition. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are the two most important long-chain omega-3 (-3) PUFAs involved in human physiology, and both industries are almost exclusively based on microalgae. In addition, algae produce phytosterols that reduce serum cholesterol. Here we determined the growth rates, biomass yields, PUFA and sterol content, and daily gain of eight strains of marine…
In vitro antifungal activity of bioactive peptides produced by Lactobacillus plantarum against Aspergillus parasiticus and Penicillium expansum
2017
Abstract Food spoilage caused by mycotoxigenic moulds represents an important problem in food security. The antimicrobial peptides are compounds of natural origin constituted by a variable number (5–100) of amino acids held together through peptide bonds. In this work, the cell free supernatants (CFSs) containing peptides obtained from four strains of LAB were lyophilized, filtered and tested to determine the antifungal activity against Aspergillus Parasiticus and Penicillium expansum . CFS obtained by Lactobacillus plantarum showed the highest inhibition activity. CFS was fractionated by size exclusion chromatography and injected into the liquid chromatography coupled to diode array detect…