Structural membrane. Medical search. Frequent questions

The lipid bilayer of cell membranes is impermeable to large and polar molecules but permeable to water molecules and other small uncharged molecules like O 2 and CO 2 . (wikibooks.org)
The availability of free energy is one of the factors that determine if a molecule will move across a membrane, the other being the permeability of the molecule in the lipid bilayer. (wikibooks.org)
Hydrophobic regions of membrane proteins, normally embedded in the membrane lipid bilayer, are now surrounded by a layer of detergent molecules and the hydrophilic regions are exposed to the aqueous medium. (sigmaaldrich.com)
When low concentrations of a detergent are added to biological membranes (a), the detergent monomers (shown in red with single tails) perturb the membrane structurally by partitioning into the lipid bilayer (b). (sigmaaldrich.com)
Solute transport on the sub 100 ms scale across the lipid bilayer membrane of individual proteoliposomes. (lu.se)

and his colleagues at Columbia University, the New York Structural Biology Center and Brookhaven National Laboratory used high-intensity X-rays to produce snapshots of TSPO alone and with a compound similar to the anti-anxiety drug Valium. (nih.gov)
Journal of Membrane Biology 2014). (mcgill.ca)
Molecular Membrane Biology 2013, 30 (3):246-260. (lu.se)
Current Opinion in Structural Biology 2006, 16 (4):447-456. (lu.se)

The presence of MPs in the hydrophobic cell membrane makes them difficult to be isolated in their functional forms and to be crystallized for further steps to a 3D-structure resolution and ultimately to be used as targets in the structure-based drug design approaches. (scholarsresearchlibrary.com)
While high resolution structures of membrane nanomachines are undeniably pertinent, our ability to leverage structure against function, requires us to have access to their conformational changes and functional states. (silverchair.com)
The identification of this pore binding site sheds light on the mechanism of barbiturate inhibition of cationic pLGICs and allows the rationalization of several structural and functional features previously observed for barbiturates. (nih.gov)
Since micelle-forming detergents provide an amphipathic environment that can mimic lipid bilayers, their use as solubilizing agents is essential for functional and structural investigations. (sigmaaldrich.com)
The results indicate that emission from dental light curing units can affect the oral mucous membrane and may reduce its functional abilities. (who.int)

The database can accelerate therapeutic developments and biotechnological applications of cancer-related membrane proteins. (mit.edu)

The Membrane Protein Structural Dynamics Consortium (MPSDC) is a large scale collaborative consortium composed of an interdisciplinary team of scientists who use biophysical and computational methods to understand how the structure and movement of membrane proteins determine their functions. (wikipedia.org)
The MPSDC was largely spurred by the urgent, compelling need for high-resolution approaches to membrane protein structure and dynamics. (wikipedia.org)
The diversity of the photosynthesis proteins due to evolution upon adaptation and exploitability is intriguing for researchers from all fields of science to understand aspects of structural diversity, function and dynamics. (rug.nl)
The 56th Annual Biophysical Society Meeting is fast approaching, and this year members of the Membrane Protein Structural Dynamics Consortium (MPSDC) have collaborated on no less than 72 presentations and posters taking place in various subgroups, platforms, symposia, mini-symposia, and workshops. (memprotein.org)
Understanding the mechanism underpinning membrane-related function requires detailed characterisation of membrane protein structure and dynamics. (silverchair.com)
Other emerging structural techniques such as pulsed electron double resonance (PELDOR or DEER) have contributed invaluable insights into membrane protein structural dynamics [ 4-6 ]. (silverchair.com)

Common applications include cell lysis, solubilization of membrane proteins and lipids, protein crystallization, and reduction of background staining in blotting experiments. (sigmaaldrich.com)

Thus, surface antigens, membrane particles, and nucleocapsids attached to the cell membrane are mobile within the plane of the membrane during viral maturation. (rupress.org)

However, for further physicochemical and biochemical characterization of membrane proteins, it is often necessary to remove the unbound detergent. (sigmaaldrich.com)

This asymmetry is maintained by the Mla pathway, a six-component system that is widespread in Gram-negative bacteria and is thought to mediate retrograde transport of misplaced phospholipids from the outer leaflet of the OM to the cytoplasmic membrane 4 . (nature.com)
TonB, partner protein of FhuA, is one of three proteins from the energy-transducing complex TonB-ExbB-ExbD that is embedded in the cytoplasmic membrane. (mcgill.ca)

Two structural studies have now shed light on the mysterious mitochondrial membrane protein TSPO. (nih.gov)
those of protein transport recent studies using yeast as a model system began to provide intriguing insights into phospholipid exchange between the ER and mitochondria as well as between the mitochondrial outer and inner membranes. (biongenex.com)

The Consortium conducts research on membrane protein function of energy transduction in signaling (ion channels and receptors) and energy interconversion (transporters and pumps) from a mechanistic perspective. (wikipedia.org)
This protein mainly interacts with ion channels and ion transporters, which are complexes of proteins that move charged atoms (ions) across cell membranes. (medlineplus.gov)
Ankyrin-B ensures these channels and transporters are in their proper locations in the cell membrane so they can regulate the flow of ions into and out of cardiac muscle cells. (medlineplus.gov)
Although the channels and transporters are produced normally by the cell, they are unable to function if they are not inserted correctly into the cell membrane. (medlineplus.gov)

In contrast to previous structures determined solely in detergent micelles, the structure in bilayers contains information about the spatial arrangement of the protein within the membrane, and thus provides insights to the bacteriophage assembly process from membrane-inserted to bacteriophage-associated protein. (rcsb.org)
While structures of membrane-associated intermediates would provide tremendous insights into the pathology and aid in the design of compounds to potentially treat the diseases, it has not been feasible to overcome the challenges posed by the cell membrane. (elifesciences.org)
The seventh international conference on " Structural Membranes 2015 TextileComposites and Inflatable Structures" will be organized on Oct. 19-21 in Barcelona. (fabricarchitecturemag.com)
As in previous editions, the state-of-the-art research and technology for design, analysis, construction and maintenance of membrane structures will be addressed. (fabricarchitecturemag.com)
As a consequence, membranes proteins account for less than 5% of the 3D-structures resolved. (scholarsresearchlibrary.com)
One way scientists can learn more about how membrane proteins function-and how medicines might interact with them-is to determine their structures. (nih.gov)
Over the last decade, progresses in native MS have allowed the retention of intact membrane protein structures into the gas phase of a mass spectrometer and more spectacularly, to characterise lipid binding events to such proteins [ 9-16 ]. (silverchair.com)
To further develop analytical and conceptual understanding of structural action through the design of elements and simple structures. (bath.ac.uk)
analytical and conceptual understanding of structural action through the design of elements and simple structures, and knowledge of elements of construction technology. (bath.ac.uk)
In eukaryotic cells complex membrane structures called organelles are highly designed to exert specialized functions. (biongenex.com)
In this study, we present the first X-ray structures of barbiturates bound to GLIC, a cationic prokaryotic pLGIC with excellent structural homology to other relevant channels sensitive to general anesthetics and, as shown here, to barbiturates, at clinically relevant concentrations. (nih.gov)
Recent advances in biophysical methods have been able to shed more light on the structures of helical bundles formed by the transmembrane segments of bitopic membrane proteins. (huji.ac.il)
Finally, the structures of the best characterized instances of transmembrane α-helical bundles formed by bitopic membrane proteins are described in detail. (huji.ac.il)
Our on-going research collaborations with colleagues world-wide emphasize structural determinants of MPs required for transport, including solving their 3-D structures by X-ray crystallography. (mcgill.ca)

In addition, the Mla system was recently shown to regulate outer membrane vesicle formation 16 . (nature.com)

Hom (Helicobacter outer membrane) family of OMPs in H. pylori consists of four members (HomA, B, C and D). In the H. pylori genome jhp 0870 open-reading frame (ORF) that codes for HomB outer membrane protein is associated with many stomach diseases and is a novel co-marker for peptic ulcer disease (PUD) 9 , 10 . (nature.com)

1 These integral membrane proteins (IMPs) ( Figure 2 ) are not soluble in aqueous solutions as they aggregate to protect their hydrophobic domains, but are soluble in detergent solutions as micelles formed by detergents are analogous to the bilayers of the biological membranes. (sigmaaldrich.com)

Mitochondria have proteins that span their membranes to control the flow of messages and materials moving into and out of the organelle. (nih.gov)
Ankyrins help organize the cell's structural framework (the cytoskeleton) and link certain proteins that span the cell membrane to this framework. (medlineplus.gov)

Structural membrane biochemistry and method. (hhmi.org)
Even though studying membrane proteins is a major challenge in protein biochemistry, they remain an important area of study due to their significant biological and pharmacological relevance. (sigmaaldrich.com)

The Gram-negative bacterial outer membrane (OM) is a unique bilayer that forms an efficient permeation barrier to protect the cell from noxious compounds 1 , 2 . (nature.com)
This overall architecture replicates green bacterial light-harvesting function whereby these assemblies exhibit long-range order and three-dimensional morphology similar to native chlorosomes and are capable of energy transfer internally and to external acceptors, located in a supporting biomimetic polymer membrane. (nau.edu)
The Coulton research group studies membrane proteins (MPs) that are required for transport of iron, an essential nutrient, across the bacterial cell envelope. (mcgill.ca)

Unfortunately, major detergents tend to unfold these proteins as they are in fast-exchange equilibrium with micelles, weakening the compactness of the membrane region and leading to a partial-to-severe loss of functionality. (scholarsresearchlibrary.com)
Excess detergent is normally employed in solubilization of membrane proteins to ensure complete dissolution of the membrane and provide a large number of single protein molecule containing micelles. (sigmaaldrich.com)
Structure and Stability of the Spinach Aquaporin SoPIP2;1 in Detergent Micelles and Lipid Membranes. (lu.se)

MlaC probably accepts a phospholipid from MlaA and shuttles it to the ABC transporter for ATP-dependent plasma membrane insertion 5 . (nature.com)
HvPIP1;6, a Barley (Hordeum vulgare L.) Plasma Membrane Water Channel Particularly Expressed in Growing Compared with Non-Growing Leaf Tissues. (lu.se)

Although the basement membrane (BM) is located at tissue interfaces, its mode of action in inter-tissue interactions remains poorly understood, mainly because the molecular and structural details of the BM at distinct inter-tissue interfaces remain unclear. (biorxiv.org)
To investigate the features of corneal epithelial basement membrane dystrophy using spectral-domain optical coherence tomography (SD OCT) and to examine the reliability of SD OCT in distinguishing epithelial basement membrane dystrophy from the normal cornea. (entokey.com)
Forty-five individuals with epithelial basement membrane dystrophy and 45 age- and sex-matched controls with normal corneas were examined, and SD OCT scans of their corneas were performed. (entokey.com)
In vivo confocal microscopy was performed to confirm or rule out the diagnosis of epithelial basement membrane dystrophy. (entokey.com)
The structural corneal changes occurring in eyes with epithelial basement membrane dystrophy based on SD OCT findings were described. (entokey.com)
Epithelial abnormalities were observed in 86 of 87 eyes with epithelial basement membrane dystrophy (45 patients) on SD OCT scans. (entokey.com)
The 2 main features were the presence of an irregular and thickened epithelial basement membrane duplicating or insinuating into the corneal epithelium layer, or both, and the presence of hyperreflective dots. (entokey.com)
We found a perfect correlation between in vivo confocal microscopy and SD OCT findings in the diagnosis of epithelial basement membrane dystrophy (κ = 0.98). (entokey.com)
SD OCT provides an accurate assessment of the structural changes occurring in eyes with epithelial basement membrane dystrophy. (entokey.com)
Corneal epithelial basement membrane dystrophy (Online Mendelian Inheritance in Man 121820) -also known as Cogan microcystic dystrophy, map-dot-fingerprint dystrophy, or microcystic corneal dystrophy-is the most common of the anterior corneal dystrophies. (entokey.com)
Although, as a general rule, epithelial basement membrane dystrophy is asymptomatic, approximately 10% of patients develop painful, recurrent epithelial erosions. (entokey.com)
This dystrophy is characterized, histologically, by an abnormal basement membrane that protrudes into the epithelium and the presence of intraepithelial microcysts. (entokey.com)
Over the last decade, in vivo confocal microscopy has provided greater insight into the morphologic anomalies that occur in eyes with corneal epithelial basement membrane dystrophy, thereby improving our understanding of the disease. (entokey.com)
We performed a prospective study of patients with corneal epithelial basement membrane dystrophy seeking treatment at an ophthalmic unit in Paris. (entokey.com)
The main aim of the study was to investigate the SD OCT features of corneal epithelial basement membrane dystrophy. (entokey.com)
We also evaluated whether these SD OCT features permit eyes with corneal epithelial basement membrane dystrophy to be distinguished from normal eyes. (entokey.com)

These results provide mechanistic insights into the membrane-enhanced structural stability of protofibrillar Aβ oligomers and the first step of Aβ-induced membrane disruption at the atomic level. (tau.ac.il)

The three-dimensional structure of the membrane-bound form of the major coat protein of Pf1 bacteriophage was determined in phospholipid bilayers using orientation restraints derived from both solid-state and solution NMR experiments. (rcsb.org)
Specifically, we demonstrate that the 2.5 kDa, poly(ethylene oxide)-block-poly(butadiene) (PEO-b-PBD), exhibits sufficient morphological flexibility as a membrane material and enables generation of mimics of three-dimensional chlorosomes as well as supported membrane bilayers containing energy acceptors. (nau.edu)
The POPG lipid bilayers enhance the structural stability of protofibrillar Aβ trimers by stabilizing inter-peptide β-sheets and D23-K28 salt-bridges. (tau.ac.il)

Fifty-one firefighters in two groups, 25 without respiratory protection and 26 wearing cartridge respirators, were monitored for exposure to products of combustion and changes in spirometric measurements and lung permeability following overhaul of a structural fire. (cdc.gov)
Testing at baseline and 1 hour after overhaul included forced vital capacity (FVC), forced expiratory volume in one second (FEV1), serum Clara cell protein (CC16), and serum surfactant-associated protein A (SP-A). Overhaul increased CC16 in both groups, indicating increased alveolarcapillary membrane permeability. (cdc.gov)

The Scientific Cores provide research support and develop new methodologies in the following fields: Membrane protein expression and production, synthetic antigen binder generation, and the use of innovative computational methods to interpret and supplement existing experimental methods. (wikipedia.org)
The fractured membranes of viral buds are continuous sheets of these small particles, and the spacing between both nucleocapsids and stripes of surface antigen in buds is less than in the surrounding cell membrane. (rupress.org)
Detached virus is covered with a continuous layer of viral antigen, has unusually large but no small particles on its membrane surfaces exposed by freeze-fracturing, and no longer has nucleocapsids aligned under its surface. (rupress.org)

There exists an exchange of molecules and ions in and out of the cell wall, as well as in and out of membrane-bounded intracellular compartments such as the nucleus, ER, and mitrochondria. (wikibooks.org)

ROSETTA and MD simulations resulted in a unique b-strand structure distinct from the conventional amyloid b-hairpin and revealed that the nucleating NFGAIL region remains flexible and accessible within this isolated intermediate, suggesting a mechanism by which membrane-associated aggregation may be propagated. (elifesciences.org)
Structural mechanism of plant aquaporin gating. (lu.se)

Cellular electron cryo-tomography revealed a protein layer showing two distinct hexagonal lattices at its membrane-proximal and membrane-distant faces, respectively. (princeton.edu)
Techniques such as computer structural prediction, transmission electron microscopy, circular dichroism in various detergent solutions, X-ray crystallization, laser scattering and nuclear magnetic resonance was used to characterize the secondary, tertiary and quaternary structure as well as the physical behaviors of this pharmacological interested fragment. (edu.hk)

When ΔG is positive the transport is active, an input of energy is needed to move a molecule up a concentration gradient, contrary to ΔG being negative the transport is passive, which means that such molecules will pass through a membrane down their own gradient, simple diffusion. (wikibooks.org)

This work demonstrates the potential of short-chain amphiphilic block copolymers in generating self-assembled, bio-mimetic membrane architectures, and in doing so, generates scalable, spatial-energetic landscapes for photonic applications. (nau.edu)

In this short review, we outline recent progresses in dissecting the conformational mechanisms of membrane proteins using HDX-MS. We further describe how the use of computational strategies can aid the interpretation of experimental data and enable visualisation of otherwise intractable membrane protein states. (silverchair.com)

These ORFs code for the envelope protein, glycoproteins (2b-5), membrane, and nucleocapsid proteins. (cdc.gov)
Membrane glycoproteins that constitute the ZONA PELLUCIDA in mammals and function in the recognition and binding of SPERMATOZOA. (bvsalud.org)

Comparisons between the membrane-bound form of the coat protein and the previously determined structural form found in filamentous bacteriophage particles demonstrate that it undergoes a significant structural rearrangement during the membrane-mediated virus assembly process. (rcsb.org)
Finally, regions of the membrane displaying twisted strands protrude to form ridges or bulges, and the freeze-fractured membrane surrounding these protrusions is characterized by an abundance of particles small than those found on the rest of the cell membrane. (rupress.org)

Furthermore, the N-terminal amphipathic helix (V2-G17) tilts away from the membrane surface and becomes parallel with the transmembrane helix to form one nearly continuous long helix. (rcsb.org)
The N-terminal helix and the hinge that connects it to the transmembrane helix are significantly more dynamic than the rest of the protein, thus facilitating structural rearrangement during bacteriophage assembly. (rcsb.org)
Arkin, IT 2002, ' Structural aspects of oligomerization taking place between the transmembrane α-helices of bitopic membrane proteins ', Biochimica et Biophysica Acta - Biomembranes , vol. 1565, no. 2, pp. 347-363. (huji.ac.il)

Structural MS has emerged as a powerful tool for characterising protein structure and function, complementing high-resolution methods [ 7-9 ]. (silverchair.com)

Membrane-assisted amyloid formation is implicated in human diseases, and many of the aggregating species accelerate amyloid formation and induce cell death. (elifesciences.org)
However, the Aβ-lipid interactions and how these induce membrane perturbation and disruption at the atomic level and the consequences for the Aβ organization are not entirely understood. (tau.ac.il)

Structural damage of the ventral artery was quantified by vacuole count using Toluidine blue staining whereas biochemical changes were assessed by nitrotyrosine (NT) staining. (cdc.gov)

To solve this problem, the cell membrane contains proteins that are selective for unique, water soluble molecules. (wikibooks.org)
Diffusion is the process by which molecules migrate over the cell membrane from areas of higher concentration to areas of lower concentration. (wikibooks.org)
MPs play key roles in the transport of a large panel of compounds through the cell membrane. (scholarsresearchlibrary.com)
Vero cells productively infected with the Halle strain of measles virus have been studied by means of surface replication, freeze-fracturing, and surface labeling with horseradish peroxidase-measles antibody conjugate in order to examine changes in the structure of the cell membrane during viral maturation. (rupress.org)
At this stage, label for viral antigens on the surface of the cell membrane is organized into stripes lying on the crests of strands. (rupress.org)
Developing new tools are therefore pertinent for improving our fundamental knowledge of how membrane proteins function in the cell. (silverchair.com)
These results suggest that PI 3-kinase in signet ring cell carcinoma is recruited to the membrane and activated by the binding to the 200-kDa protein. (edrc2013.org)
At least one ANK2 gene mutation prevents ankyrin-B from getting to the cell membrane where it is needed to function. (medlineplus.gov)

Complete removal of detergent could result in aggregation due to the clustering of hydrophobic regions and, hence, may cause precipitation of membrane proteins. (sigmaaldrich.com)

H. pylori attaches and colonizes to the human epithelium using some of their outer membrane proteins (OMPs). (nature.com)

In this context, surfactants (detergents) are used as key components during the extraction and structural studies of MPs. (scholarsresearchlibrary.com)
How Do Detergents Solubilize Membrane Proteins? (sigmaaldrich.com)
Membrane solubilization by detergents can be described as a three stage process where the detergent-lipid-protein ratio is an important factor ( Figure 3 ). (sigmaaldrich.com)
Stages in the solubilization of biological membranes by detergents. (sigmaaldrich.com)

The glycosylated mature peptide is one of the structural components of the zona pellucida and functions in secondary binding and penetration of acrosome-reacted spermatozoa. (nih.gov)
A membrane glycoprotein of the ZONA PELLUCIDA that functions in oocyte recognition of ACROSOME-reacted sperm. (bvsalud.org)
It is essential for the formation and structural integrity of the ZONA PELLUCIDA. (bvsalud.org)

CrMP-Sol also presents QTY-enabled water-soluble designs to facilitate native membrane protein studies despite natural hydrophobicity. (mit.edu)

Therefore the primary function of the ERMES as the phospholipid transport machinery is still under argument although its membrane tethering function is now widely recognized. (biongenex.com)
Understanding the structure and function of membrane proteins requires their careful isolation in the native form in a highly purified state. (sigmaaldrich.com)
To gain insight into the function of MMADHC, recombinant isoforms were purified and low-resolution structural features were determined. (mcgill.ca)

Affinity tags can reduce merohedral twinning of membrane protein crystals. (lu.se)

Osmosis is very important in biological systems because many membranes are semipermeable. (wikibooks.org)
Biological membranes consist of phospholipids that contain two hydrophobic groups connected to a polar head. (sigmaaldrich.com)

Membrane proteins (MPs) account for 25-30% of proteomes and present over 70% of the pharmaceutical targets. (scholarsresearchlibrary.com)

Cargo is recruited, enveloped at the inner nuclear membrane (INM), and delivered by membrane fusion at the outer nuclear membrane. (princeton.edu)
Membrane Trafficking, Fusion, and Synaptic. (hhmi.org)

Sewage Membrane Structure has a maximum span of 40 meters and adopts the form of truss structure covered with PVC membrane. (ecplaza.net)
We found that the trimer structure related to Alzheimer's disease brain tissue (2M4J) is the most stable both in water solution and at membrane surface, and displays slightly stronger membrane perturbation capability. (tau.ac.il)

Other possible hazardous substances and situations such as chemical and structural hazards are also included in the website to ensure the health and safety of workers. (cdc.gov)

Membrane proteins are critical mediators for tumor progression and present enormous therapeutic potentials. (mit.edu)

The disaster management page also offers information on other hazards such as asbestos, carbon monoxide, confined spaces, chemical and structural hazards and provides guidance on identifying and handling human remains. (cdc.gov)

Anatomy54

Organisms12

Diseases2

Chemicals and Drugs99

Analytical, Diagnostic and Therapeutic Techniques and Equipment29

Phenomena and Processes57

Disciplines and Occupations4

Technology, Industry, Agriculture7

Information Science3

Health Care1

Lipid bilayer5

Biology4

Functional5

Related membrane proteins1

Dynamics6

Lipids1

Attached to the cell membrane1

Characterization1

Cytoplasmic membrane2

Mitochondrial2

Transporters4

Structures14

Vesicle formation1

Outer membrane protein1

Integral membrane1

Proteins that span2

Biochemistry2

Bacterial3

Micelles3

Plasma membrane2

Basement membrane16

Insights1

Bilayers3

Permeability2

Antigen3

Intracellular1

Mechanism2

Electron2

Molecule1

Architectures1

Conformational1

Glycoproteins2

Particles2

Transmembrane3

Protein structure1

Induce2

Biochemical1

Cell8

Aggregation1

Epithelium1

Detergents4

Zona pellucida3

Water soluble1

Function3

Crystals1

Biological2

Targets1

Fusion2

Structure2

Substances1

Tumor1

Carbon1