Search results for "PROTEIN"
showing 10 items of 21431 documents
Triterpene glycosides from Blighia welwitschii and evaluation of their antibody recognition capacity in multiple sclerosis
2020
Multiple sclerosis (MS) in a multifactorial autoimmune disease in which reliable biomarkers are needed for therapeutic monitoring and diagnosis. Autoantibodies (autoAbs) are known biomarker candidates although their detection in biological fluids requires a thorough characterization of their associated antigens. Over the past twenty years, a reverse chemical-based approach aiming to screen putative autoantigens has underlined the role of glycans, in particular glucose, in MS. Despite the progress achieved, a lack of consensus regarding the nature of innate antigens as well as difficulties proposing new synthetic glucose-based structures have proved to be obstacles. Here is proposed a strate…
III. Biochemistry of S-layers
1997
During evolution prokaryotes have developed different envelope structures exterior to the cell wall proper. Among these surface components are regularly arranged S-layers and capsules. The structural characterization and the detailed chemical analysis of these surface molecules is a prerequisite to understand their biosynthesis and functional role(s) at the molecular level. Of particular interest are the glycosylated S-layer proteins which belong to the first prokaryotic glycoproteins ever described. Their characterization was performed on strains belonging to the thermophilic Bacillaceae and included structural studies and experiments to learn about the pathways for the glycan biosynthesis…
Changes in lipid composition in tobacco cells treated with cryptogein , an elicitor from Phytophthora cryptogea
1995
Abstract Changes in lipid composition occurred when tobacco cells (Nicotiana tabacum var. Xanthi) were treated with cryptogein, a proteinaceous elicitor from Phytophthora cryptogea. The most striking change was an increase in acylated steryl glycosides and steryl esters levels, certainly resulting from the glycosylation and/or esterification of free sterols. Moreover, in vivo pulse-labelling experiments with [14C]acetate also showed that a progressive decline in the incorporation rate of [14C]acetate into free sterols started with the induction of sesquiterpenoid synthesis and lasted when sesquiterpenoid synthesis stops. This phenomenon was accompanied by a significant increase in the synth…
Isolation and characterization of a Vitis vinifera transcription factor, VvWRKY1, and its effect on responses to fungal pathogens in transgenic tobac…
2007
International audience; Pathogen attack represents a major problem for viticulture and for agriculture in general. At present, the use of phytochemicals is more and more restrictive, and therefore it is becoming essential to control disease by having a thorough knowledge of resistance mechanisms. The present work focused on the trans-regulatory proteins potentially involved in the control of the plant defence response, the WRKY proteins. A full-length cDNA, designated VvWRKY1, was isolated from a grape berry library (Vitis vinifera L. cv. Cabernet Sauvignon). It encodes a polypeptide of 151 amino acids whose structure is characteristic of group IIc WRKY proteins. VvWRKY1 gene expression in …
Bridging the Knowledge Gap for the Impact of Non-Thermal Processing on Proteins and Amino Acids
2019
Proteins represent one of the major food components that contribute to a wide range of biophysical functions and dictate the nutritional, sensorial, and shelf-life of food products. Different non-thermal processing technologies (e.g., irradiation, ultrasound, cold plasma, pulsed electric field, and high-pressure treatments) can affect the structure of proteins, and thus their solubility as well as their functional properties. The exposure of hydrophobic groups, unfolding followed by aggregation at high non-thermal treatment intensities, and the formation of new bonds have been reported to promote the modification of structural and functional properties of proteins. Several studies reported …
Are mussels able to distinguish underwater sounds? Assessment of the reactions of Mytilus galloprovincialis after exposure to lab-generated acoustic …
2016
This study examined the effects of lab-generated acoustic signals on the behaviour and biochemistry of Mediterranean mussels (Mytilus galloprovincialis). The experiment was carried out in a tank equipped with a video-recording system using six groups of five mussels exposed to five acoustic treatments (each treatment was replicated three times) for 30 min. The acoustic signals, with a maximum sound pressure level of 150 dB rms re 1 μPa, differed in frequency range as follows: low (0.1–5 kHz), mid-low (5–10 kHz), mid (10–20 kHz), mid-high (20–40 kHz) and high (40–60 kHz). The exposure to sweeps did not produce any significant changes in the mussels' behaviour. Conversely, the specimens expos…
Variation in Hsp70 Levels after Cold Shock: Signs of Evolutionary Responses to Thermal Selection among Leptinotarsa decemlineata Populations
2012
Individuals of widely spread species are expected to show local adaption in temperature tolerance as they encounter a range of thermal conditions. We tracked thermal adaptations of the Colorado potato beetle (Leptinotarsa decemlineata) that invaded Europe within the last 100 years. It has occupied various conditions although, like the majority of invasive species, it lost a measurable amount of neutral genetic variation due to bottleneck effect when it invaded Europe. We exposed diapausing beetles originated from three different latitudes (54°N, 59°N, 60°N) to cold shock (−5°C, 1.5 hrs) in order to test if beetles from the northern populations express differential levels of cold-induced and…
Effects of Bacillus thuringiensis δ-Endotoxins on the Pea Aphid ( Acyrthosiphon pisum )
2009
ABSTRACT Four Bacillus thuringiensis δ-endotoxins, Cry3A, Cry4Aa, Cry11Aa, and Cyt1Aa, were found to exhibit low to moderate toxicity on the pea aphid, Acyrthosiphon pisum , in terms both of mortality and growth rate. Cry1Ab was essentially nontoxic except at high rates. To demonstrate these effects, we had to use exhaustive buffer-based controls.
Involvement of plasma membrane proteins in plant defense responses. Analysis of the cryptogein signal transduction in tobacco
1999
International audience; Cryptogein, a 98 amino acid protein secreted by the fungus Phytophthora cryptogea, induces a hypersensitive response and systemic acquired resistance in tobacco plants (Nicotiana tabacum var Xanthi). The mode of action of cryptogein has been studied using tobacco cell suspensions. The recognition of this elicitor by a plasma membrane receptor leads to a cascade of events including protein phosphorylation, calcium influx, potassium and chloride effluxes, plasma membrane depolarization, activation of a NADPH oxidase responsible for active oxygen species (AOS) production and cytosol acidification, activation of the pentose phosphate pathway, and activation of two mitoge…
Tobacco cells contain a protein, immunologically related to the neutrophil small G protein Rac2 and involved in elicitor-induced oxidative burst.
1997
Abstract Suspension-cultured cells of Nicotiana tabacum generated active oxygen species (AOS) when they were treated with the proteinaceous elicitor, cryptogein. This response was blocked by diphenylene iodonium, an inhibitor of the neutrophil NADPH oxidase. When microsomal extracts of tobacco cells were probed with an antibody directed against the human small G protein Rac2, two immunoreactive proteins were detected at 18.5 and 20.5 kDa. The same experiment performed with cytosolic extracts of tobacco cells led to the observation of a strong immunoreactive protein at 21.5 kDa only in the cryptogein-treated cells. The appearance of this cytosolic protein was related to the production of AOS…