Effect of TMAO on the Structure and Phase Transition of Lipid Membranes: Potential Role of TMAO in Stabilizing Cell Membranes under Osmotic Stress

2021 ◽  
Vol 125 (4) ◽  
pp. 1167-1180
Author(s):  
Archita Maiti ◽  
Snehasis Daschakraborty
Keyword(s):  
Phase Transition ◽  
Osmotic Stress ◽  
Lipid Membranes ◽  
Cell Membranes ◽  
Potential Role

scholarly journals NMR and LC-MS-Based Metabolomics to Study Osmotic Stress in Lignan-Deficient Flax

Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 767
Author(s):  
Kamar Hamade ◽  
Ophélie Fliniaux ◽  
Jean-Xavier Fontaine ◽  
Roland Molinié ◽  
Elvis Otogo Nnang ◽  
...  
Keyword(s):  
Stress Response ◽  
Osmotic Stress ◽  
Biosynthetic Pathway ◽  
Potential Role ◽  
Plant Secondary Metabolites ◽  
Wild Type ◽  
Osmotic Stress Response ◽  
Transgenic Flax ◽  
Insight Into

Lignans, phenolic plant secondary metabolites, are derived from the phenylpropanoid biosynthetic pathway. Although, being investigated for their health benefits in terms of antioxidant, antitumor, anti-inflammatory and antiviral properties, the role of these molecules in plants remains incompletely elucidated; a potential role in stress response mechanisms has been, however, proposed. In this study, a non-targeted metabolomic analysis of the roots, stems, and leaves of wild-type and PLR1-RNAi transgenic flax, devoid of (+) secoisolariciresinol diglucoside ((+) SDG)—the main flaxseed lignan, was performed using 1H-NMR and LC-MS, in order to obtain further insight into the involvement of lignan in the response of plant to osmotic stress. Results showed that wild-type and lignan-deficient flax plants have different metabolic responses after being exposed to osmotic stress conditions, but they both showed the capacity to induce an adaptive response to osmotic stress. These findings suggest the indirect involvement of lignans in osmotic stress response.

Stressing Lipid Membranes: Effects of Polymers on Membrane Structural Integrity

2012 ◽  
Vol 1480 ◽  
Author(s):  
Jia-Yu Wang ◽  
Chi-Yuan Cheng ◽  
Ravinath. Kausik ◽  
Jaemin Chin ◽  
Songi. Han ◽  
...  
Keyword(s):  
Cell Membrane ◽  
Osmotic Stress ◽  
Lipid Membranes ◽  
Cell Membranes ◽  
Structural Integrity ◽  
Membrane Surface ◽  
Membrane Integrity ◽  
Biocompatible Polymers ◽  
Giant Unilamellar Vesicles ◽  
Hydration Dynamics

ABSTRACTDisruption of cell membranes triggers rapid metabolic energy exhaustion, then acute cellular necrosis. Cell membrane dysfunction due to loss of structure integrity is the pathology of tissue death in trauma, muscular dystrophies, reperfusion injuries and common diseases. It is now established that certain PEG-based biocompatible polymers, such as Poloxamer 188, Poloxamine 1107 and PEG, are effective in sealing of injured cell membranes, and thus can prevent acute necrosis if delivered within a few hours after injury. Despite these broad applications of PEG-based polymers for human health, the fundamental mechanisms of how PEG-based polymers interact with cell membranes are still under debate. Here, the effects of PEG-based biocompatible polymers on phospholipid membrane integrity under external stimuli (osmotic stress and oxidative stress) were explored using giant unilamellar vesicles (GUVs) as model cell membranes. Through fluorescence leakage assays and time-lapse fluorescence microscopy, we directly observed that the surface-adsorbed P188 can efficiently inhibits the loss of structural integrity of giant unilamellar vesicles (GUVs) under hypo-osmotic stress. We propose that the adsorption of polymers on the membrane surface is responsible for the cell membrane resealing process, while the insertion of the hydrophobic portion of the polymers increases membrane permeability. To elucidate the mechanism by which hydrophilic polymers help restore membrane integrity while their hydrophobic counterparts disrupt it, 1H Overhauser Dynamic Nuclear Polarization (ODNP)-NMR spectroscopy, a newly developed NMR technique that provides unprecedented resolution for differentiating weak surface adsorption versus translocation of polymers to membranes, was employed to sensitively detect polymer-lipid membrane interactions through the modulation of local hydration dynamics in lipid membranes. Our study shows that P188—the most hydrophilic poloxamer known as a membrane sealant—weakly adsorbs onto the membrane surface, yet effectively retards membrane hydration dynamics. Contrarily, P181—the most hydrophobic poloxamer known as a membrane permeabilizer—initially penetrates past lipid headgroups and enhances intrabilayer water diffusivity. Consequently, our results illustrate that the relative hydrophilic/hydrophobic ratio of the polymer dictates its functions. These findings gleaned from local hydration dynamics are well supported by our thermodynamics and fluorescence data.

scholarly journals Decoding the Membrane Activity of the Cyclotide Kalata B1

2011 ◽  
Vol 286 (27) ◽  
pp. 24231-24241 ◽  
Author(s):  
Sónia Troeira Henriques ◽  
Yen-Hua Huang ◽  
K. Johan Rosengren ◽  
Henri G. Franquelim ◽  
Filomena A. Carvalho ◽  
...  
Keyword(s):  
Lipid Membranes ◽  
Cyclic Peptides ◽  
Cell Membranes ◽  
Hydrophobic Interactions ◽  
Biological Activities ◽  
Large Family ◽  
Kalata B1 ◽  
Raft Domains ◽  
Anti Hiv

Cyclotides, a large family of cyclic peptides from plants, have a broad range of biological activities, including insecticidal, cytotoxic, and anti-HIV activities. In all of these activities, cell membranes seem likely to be the primary target for cyclotides. However, the mechanistic role of lipid membranes in the activity of cyclotides remains unclear. To determine the role of lipid organization in the activity of the prototypic cyclotide, kalata B1 (kB1), and synthetic analogs, their bioactivities and affinities for model membranes were evaluated. We found that the bioactivity of kB1 is dependent on the lipid composition of target cell membranes. In particular, the activity of kB1 requires specific interactions with phospholipids containing phosphatidylethanolamine (PE) headgroups but is further modulated by nonspecific peptide-lipid hydrophobic interactions, which are favored in raft-like membranes. Negatively charged phospholipids do not favor high kB1 affinity. This lipid selectivity explains trends in antimicrobial and hemolytic activities of kB1; it does not target bacterial cell walls, which are negatively charged and lacking PE-phospholipids but can insert in the membranes of red blood cells, which have a low PE content and raft domains in their outer layer. We further show that the anti-HIV activity of kB1 is the result of its ability to target and disrupt the membranes of HIV particles, which are raft-like membranes very rich in PE-phospholipids.

POPDC proteins and cardiac function

2019 ◽  
Vol 47 (5) ◽  
pp. 1393-1404 ◽  
Author(s):  
Thomas Brand
Keyword(s):  
Potential Role ◽  
Striated Muscle ◽  
Short Review ◽  
Effector Proteins ◽  
Muscle Disease ◽  
Disease Genes ◽  
Protein Protein Interaction ◽  
Interaction Partners ◽  
And Function

Abstract The Popeye domain-containing gene family encodes a novel class of cAMP effector proteins in striated muscle tissue. In this short review, we first introduce the protein family and discuss their structure and function with an emphasis on their role in cyclic AMP signalling. Another focus of this review is the recently discovered role of POPDC genes as striated muscle disease genes, which have been associated with cardiac arrhythmia and muscular dystrophy. The pathological phenotypes observed in patients will be compared with phenotypes present in null and knockin mutations in zebrafish and mouse. A number of protein–protein interaction partners have been discovered and the potential role of POPDC proteins to control the subcellular localization and function of these interacting proteins will be discussed. Finally, we outline several areas, where research is urgently needed.

1255: Potential Role of Postoperative Azotemia in Predicting Response to Interleukin-2 (IL-2) Immunotherapy Following Cytoreductive Nephrectomy for Metastatic Renal Cell Carcinoma

2007 ◽  
Vol 177 (4S) ◽  
pp. 414-414
Author(s):  
John S. Lam ◽  
Rakhee H. Gael ◽  
Tobias Klatte ◽  
Fairooz F. Kabbinavar ◽  
Arie S. Belldegrun ◽  
...  
Keyword(s):  
Renal Cell Carcinoma ◽  
Cell Carcinoma ◽  
Metastatic Renal Cell Carcinoma ◽  
Renal Cell ◽  
Potential Role ◽  
Interleukin 2 ◽  
Cytoreductive Nephrectomy

The Effect of Path Length and Display Size on Memory for Spatial Information

2012 ◽  
Vol 59 (3) ◽  
pp. 147-152 ◽  
Author(s):  
Katherine Guérard ◽  
Sébastien Tremblay
Keyword(s):  
Path Length ◽  
Potential Role ◽  
Spatial Information ◽  
Recall Performance ◽  
Minor Role ◽  
Length Effect ◽  
Serial Memory ◽  
Fixed Reference ◽  
A Minor

In serial memory for spatial information, some studies showed that recall performance suffers when the distance between successive locations increases relatively to the size of the display in which they are presented (the path length effect; e.g., Parmentier et al., 2005) but not when distance is increased by enlarging the size of the display (e.g., Smyth & Scholey, 1994). In the present study, we examined the effect of varying the absolute and relative distance between to-be-remembered items on memory for spatial information. We manipulated path length using small (15″) and large (64″) screens within the same design. In two experiments, we showed that distance was disruptive mainly when it is varied relatively to a fixed reference frame, though increasing the size of the display also had a small deleterious effect on recall. The insertion of a retention interval did not influence these effects, suggesting that rehearsal plays a minor role in mediating the effects of distance on serial spatial memory. We discuss the potential role of perceptual organization in light of the pattern of results.

The Potential Role of the Cytochrome P-450 2D6 Pharmacogenetic Polymorphism in Drug Abuse

1997 ◽  
Author(s):  
Edward M. Sellers ◽  
S. Victoria Otton ◽  
Rachel F. Tyndale
Keyword(s):  
Drug Abuse ◽  
Potential Role ◽  
Cytochrome P 450
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