Search results for "Protein"
showing 10 items of 21431 documents
Heat-sensitive UV-Vis measurements for Phytochrome
2016
Fytokromit ovat punaista valoa aistivia proteiineja, jotka säätelevät suurta joukkoa solun toimintoja kasvi-, bakteeri- ja sienisoluissa. Nämä valoaktiiviset proteiinit muuntavat konformaatiotaan palautuvasti aktiivisen (Pfr) ja inaktiivisen (Pr) tilan välillä. Fytokromien aminohappojen väliset heikot vuorovaikutukset - etenkin vetysidokset - vaikuttavat lopulta laskostumiseen ja proteiinin lämpöstabiiliuteen. Fytokromit esiintyvät homodimeerisinä rakenteina, joiden monomeerit koostuvat useista domeeneista. Nämä jakautuvat N- terminaaliseen valosensitiiviseen moduuliin (PSM) ja C-terminaaliseen OutPut moduliin (OPM). PSM koostuu kolmesta domeenista (PAS-GAF ja PHY). Tässä työssä tutkittiin …
The Interconnecting Hairpin Extension "Arm": An Essential Allosteric Element of Phytochrome Activity
2023
In red-light sensing phytochromes, isomerization of the bilin chromophore triggers structural and dynamic changes across multiple domains, ultimately leading to control of the output module (OPM) activity. In between, a hairpin structure, "arm", extends from an interconnecting domain to the chromophore region. Here, by removing this protein segment in a bacteriophytochrome from Deinococcus radiodurans (DrBphP), we show that the arm is crucial for signal transduction. Crystallographic, spectroscopic, and biochemical data indicate that this variant maintains the properties of DrBphP in the resting state. Spectroscopic data also reveal that the armless systems maintain the ability to respond t…
Phytol and Heptacosane Are Possible Tools to Overcome Multidrug Resistance in an In Vitro Model of Acute Myeloid Leukemia
2022
Drug resistance is the ability of cancer cells to gain resistance to both conventional and novel chemotherapy agents, and remains a major problem in cancer therapy. Resistance mechanisms are multifactorial and involve more strictly pharmacological factors, such as P-glycoprotein (P-gp) and biological factors such as inhibitor of apoptosis proteins (IAPs) and the nuclear factor-kappa B (NF-κB) pathway. Possible therapeutic strategies for the treatment of acute myeloid leukemia (AML) have increased in recent years; however, drug resistance remains a problem for most pa-tients. Phytol and heptacosane are the major compounds of Euphorbia intisy essential oil (EO) which were demonstrated to inhi…
Function of odorant-binding proteins in the Drosophila melanogaster chemoreception
2017
National audience; Function of odorant-binding proteins in the Drosophila [i]melanogaster[/i] chemoreception. 18. rencontre du Club de neurobiologie des invertébrés
Cold Exposure Affects Lipid Metabolism, Fatty Acids Composition and Transcription in Pig Skeletal Muscle
2021
Cold exposure promotes glucose oxidation and modulates the lipid metabolism in adipose tissue, but it is still not fully clear whether cold exposure could affect meat quality and fatty acid metabolism in skeletal muscle of pig in vivo. Here, we kept finishing pigs under cold or room temperature overnight and determined the effects of cold exposure on meat quality, fatty acids composition and transcriptional changes in skeletal muscle of pigs. We found that cold exposure significantly reduced the meat colour24 h and pH24 h, without affecting carcass characteristics and other meat quality traits. Considerable changes were found in the proportions of individual fatty acids and the total conten…
Varying plant protein sources in the diet of sea bass Dicentrarchus labrax differently affects lipid metabolism and deposition
2010
The liver activity of lipogenic enzymes, the lipid content in various tissues, and plasma lipid levels of major, were measured in sea bass (D. labrax) fed over 96 days either a, fish meal-based control diet or preparations where 70% of fish meal protein was replaced by wheat gluten singly or in combination with pea or soybean meals. Relative to the controls, sea bass fed the wheat gluten-based diet resulted in stimulated lipogenesis in liver and increased lipid deposition in muscle. The opposite occurred when a substantial amount of soybean meal was included in the diet. Mesenteric fat depots were apparently insensitive to major changes in dietary protein source in fish showing similar inta…
Toward Sustainable PLA-Based Multilayer Complexes with Improved Barrier Properties
2019
Poly(lactic acid) or PLA is currently considered as one of the most promising substitutes of conventional plastics, with low environmental impact, especially for food packaging applications. Nevertheless, some drawbacks, such as high permeability to oxygen, are still limiting its industrial applications. The objective of this study was to highly increase the oxygen barrier performance of PLA without compromising its sustainable nature and following the principles of circular economy perspective. Coproducts coming from mill industries, such as wheat gluten proteins (WG), were used to produce PLA-WG-PLA multilayer complexes with improved barrier performance. Different technologies of industri…
Plasma PAF-acetylhydrolase in patients with coronary artery disease: results of a cross-sectional analysis.
2003
Inflammation underlies both onset and perpetuation of atherosclerosis. Plasma lipoproteins transport the platelet-activating factor-acetylhydrolase (PAF-AH) with potentially anti-inflammatory activities. Our aim was to determine whether PAF-AH activity was associated with inflammatory markers and with coronary artery disease (CAD). PAF-AH activity and a panel of inflammatory mediators were measured in plasma of 496 patients with CAD and in 477 controls; 276 patients presented with stable angina pectoris and 220 with acute coronary syndrome (ACS). Individuals within the highest quartile of PAF-AH activity had an 1.8-fold increase in CAD risk [95% confidence interval (CI), 1.01 to 3.2; P = 0.…
Predictive First-principles Modeling of a Photosynthetic Antenna Protein : The Fenna-Matthews-Olson Complex
2020
High efficiency of light harvesting in photosynthetic pigment-protein complexes is governed by evolutionary-perfected protein-assisted tuning of individual pigment properties and inter-pigment interactions. Due to the large number of spectrally overlapping pigments in a typical photosynthetic complex, experimental methods often fail to unambiguously identify individual chromophore properties. Here we report a first principles-based modeling protocol capable of predicting properties of pigments in protein environment to a high precision. The technique was applied to successfully uncover electronic properties of the Fenna-Matthews-Olson (FMO) pigment-protein complex. Each of the three subunit…
Hetero-difunctional dimers as building blocks for the synthesis of poly(amidoamine)s with hetero-difunctional chain terminals and their derivatives
2012
This article reports on a simple and straightforward preparation method of poly(amidoamine)s (PAAs) with hetero-difunctional chain ends as well as of several up to now hardly obtainable PAA derivatives of biotechnological interest, such as for instance PAAs of controlled molecular weight and narrow polydispersity mono-functionalized at one end with an acrylamide group, PAAs with star-like molecular architecture, graft-PAA-protein conjugates, “tadpole-like” PAA conjugates with hydrophobic moieties able to self assemble into nanoparticles in aqueous media. The key step was to design suitable building blocks consisting of hetero-difunctional dimers (HDDs). In particular, the HDDs considered we…