Search results for "Lysophosphatidylcholines"
showing 10 items of 12 documents
Activation of the plant plasma membrane H+ -ATPase. Is there a direct interaction between lysophosphatidylcholine and the C-terminal part of the enzy…
1996
The antagonistic effects of the fungal toxin beticolin-1 and of L-alpha-lysophosphatidylcholine (lysoPC) were investigated on the plasma membrane H+-ATPase of the plant Arabidopsis thaliana (isoform 2) expressed in yeast, using both wild-type enzyme (AHA2) and C-terminal truncated enzyme (aha2delta92). Phosphohydrolytic activities of both enzymes were inhibited by beticolin-1, with very similar 50% inhibitory concentrations, indicating that the toxin action does not involve the C-terminal located autoinhibitory domain of the proton pump. Egg lysoPC, a compound that activates the H+-ATPase by a mechanism involving the C-terminal part of the protein, was found to be able to reverse the inhibi…
From elicitins to lipid-transfer proteins: a new insight in cell signalling involved in plant defence mechanisms.
2002
Elicitins and lipid-transfer proteins are small cysteine-rich lipid-binding proteins secreted by oomycetes and plant cells, respectively, that share some structural and functional properties. In spite of intensive work on their structure and diversity at the protein and genetic levels, the precise biological roles of lipid-transfer proteins remains unclear, although the most recent data suggest a role in somatic embryogenesis, in the formation of protective surface layers and in defence against pathogens. By contrast, elicitins are known elicitors of plant defence, and recent work demonstrating that elicitins and lipid-transfer proteins share the same biological receptors gives a new perspe…
A novel ultradeformable liposomes of Naringin for anti-inflammatory therapy
2018
[EN] Ultradeformable liposomes were formulated using naringin (NA), a flavanone glycoside, at different concentrations (3, 6 and 9 mg/mL). Nanovesicles were small size (similar to 100 nm), regardless of the NA concentration used, and monodisperse (PI<0.30). All formulations showed a high entrapment efficiency (similar to 88%) and a highly negative zeta potential (around -30 mV). The selected formulations were highly biocompatible as confirmed by in vitro studies using 3T3 fibroblasts. In vitro assay showed that the amounts (%) of NA accumulated in the epidermis (similar to 10%) could explain the anti-inflammatory properties of ultradeformable liposomes. In vivo studies confirmed the higher …
The quality of cortical network function recovery depends on localization and degree of axonal demyelination
2016
AbstractMyelin loss is a severe pathological hallmark common to a number of neurodegenerative diseases, including multiple sclerosis (MS). Demyelination in the central nervous system appears in the form of lesions affecting both white and gray matter structures. The functional consequences of demyelination on neuronal network and brain function are not well understood. Current therapeutic strategies for ameliorating the course of such diseases usually focus on promoting remyelination, but the effectiveness of these approaches strongly depends on the timing in relation to the disease state. In this study, we sought to characterize the time course of sensory and behavioral alterations induced…
Spontaneous domain formation of phospholipase A2 at interfaces: fluorescence microscopy of the interaction of phospholipase A2 with mixed monolayers …
1992
Abstract Fluorescence microscopy has recently been proven to be an ideal tool to investigated the specific interaction of phospholipase A 2 with oriented substrate monolayers. Using a dual labeling technique, it could be shown that phospholipase A 2 can specifically attack and hydrolyze solid analogous l -α-DPPC domains. After a critical extent of monolayer hydrolysis the enzyme itself starts to aggregate forming regular shaped protein domains (Grainger et al. (1990) Biochim. Biophys. Acta 1023. 365–379). In order to confirm that the existence of hydrolysis products in the mononlayer is necessary for the observed aggregation of phospholipase A 2 , mixed monolayers of d - and l -α-DPPC, l -α…
Detergent Properties Influence the Stability of the Glycophorin A Transmembrane Helix Dimer in Lysophosphatidylcholine Micelles
2012
AbstractDetergents might affect membrane protein structures by promoting intramolecular interactions that are different from those found in native membrane bilayers, and fine-tuning detergent properties can be crucial for obtaining structural information of intact and functional transmembrane proteins. To systematically investigate the influence of the detergent concentration and acyl-chain length on the stability of a transmembrane protein structure, the stability of the human glycophorin A transmembrane helix dimer has been analyzed in lyso-phosphatidylcholine micelles of different acyl-chain length. While our results indicate that the transmembrane protein is destabilized in detergents w…
Characterization of Acylating and Deacylating Activities of an Extracellular Phospholipase A2 in a Water-Restricted Environment
1994
The behavior of porcine pancreatic phospholipase A2 (ppPLA2) in monophasic low-water media has been explored, for the first time, in a systematic manner. It has been investigated how a number of variables can modulate both acylating and deacylating activities of the enzyme, and several interesting, unexpected results are presented. Among the most relevant, when placing ppPLA2 in the water-restricted environment, are the following: (i) it displays a remarkable alteration of its specificity toward the substrate polar head relative to all-water medium; (ii) it is quite severely inhibited by lysophosphatidylcholine (LPC), which has important implications, particularly concerning its acylation a…
Expressional control of the ‘constitutive’ isoforms of nitric oxide synthase (NOS I and NOS III)
1998
Nitric oxide synthase (NOS) exists in three established isoforms. NOS I (NOS1, ncNOS) was originally discovered in neurons. This enzyme and splice variants thereof have since been found in many other cells and tissues. NOS II (NOS2, iNOS) was first identified in murine macrophages, but can also be induced in many other cell types. NOS III (NOS3, ecNOS) is expressed mainly in endothelial cells. Whereas NOS II is a transcriptionally regulated enzyme, NOS I and NOS III are considered constitutively expressed proteins. However, evidence generated in recent years indicates that these two isoforms are also subject to expressional regulation. In view of the important biological functions of these …
Specific enrichment of 2-arachidonoyl-lysophosphatidylcholine in carotid atheroma plaque from type 2 diabetic patients
2016
IF 3.942; International audience; Background and aims: Diabetic patients are at high risk of stroke and coronary artery disease. Recent data suggest that arachidonic acid metabolism is altered in diabetic conditions and that these alterations contribute to accelerated atherosclerosis. Little is known about how these alterations affect the metabolism and the proportions of different lipid species within the atherosclerotic plaque. The aim of our study was to perform a targeted lipidomic analysis of human atherosclerotic lesions, with a specific focus on PUFA-containing lipid species, to reveal differences in the fatty-acid composition of plaque in diabetic patients compared with non-diabetic…
Bilobalide, a constituent of Ginkgo biloba , inhibits NMDA-induced phospholipase A 2 activation and phospholipid breakdown in rat hippocampus
2000
In rat hippocampal slices superfused with magnesium-free buffer, glutamate (1 mM) caused the release of large amounts of choline due to phospholipid breakdown. This phenomenon was mimicked by N-methyl-D-aspartate (NMDA) in a calcium-sensitive manner and was blocked by NMDA receptor antagonists such as MK-801 and 7-chlorokynurenate. The NMDA-induced release of choline was not caused by activation of phospholipase D but was mediated by phospholipase A2 (PLA2) activation as the release of choline was accompanied by the formation of lyso-phosphatidylcholine (lyso-PC) and glycerophospho-choline (GPCh) and was blocked by 5-[2-(2-carboxyethyl)-4-dodecanoyl-3,5-dimethylpyrrol-1-yl]pentano ic acid, …