Membrane Fluidity: The motion of phospholipid molecules within the lipid bilayer, dependent on the classes of phospholipids present, their fatty acid composition and degree of unsaturation of the acyl chains, the cholesterol concentration, and temperature.Membrane Lipids: Lipids, predominantly phospholipids, cholesterol and small amounts of glycolipids found in membranes including cellular and intracellular membranes. These lipids may be arranged in bilayers in the membranes with integral proteins between the layers and peripheral proteins attached to the outside. Membrane lipids are required for active transport, several enzymatic activities and membrane formation.Cell Membrane: The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells.Lipid Bilayers: Layers of lipid molecules which are two molecules thick. Bilayer systems are frequently studied as models of biological membranes.Lipids: A generic term for fats and lipoids, the alcohol-ether-soluble constituents of protoplasm, which are insoluble in water. They comprise the fats, fatty oils, essential oils, waxes, phospholipids, glycolipids, sulfolipids, aminolipids, chromolipids (lipochromes), and fatty acids. (Grant & Hackh's Chemical Dictionary, 5th ed)Membranes, Artificial: Artificially produced membranes, such as semipermeable membranes used in artificial kidney dialysis (RENAL DIALYSIS), monomolecular and bimolecular membranes used as models to simulate biological CELL MEMBRANES. These membranes are also used in the process of GUIDED TISSUE REGENERATION.Membranes: Thin layers of tissue which cover parts of the body, separate adjacent cavities, or connect adjacent structures.Diphenylhexatriene: A fluorescent compound that emits light only in specific configurations in certain lipid media. It is used as a tool in the study of membrane lipids.Fluorescence Polarization: Measurement of the polarization of fluorescent light from solutions or microscopic specimens. It is used to provide information concerning molecular size, shape, and conformation, molecular anisotropy, electronic energy transfer, molecular interaction, including dye and coenzyme binding, and the antigen-antibody reaction.Erythrocyte Membrane: The semi-permeable outer structure of a red blood cell. It is known as a red cell 'ghost' after HEMOLYSIS.Intracellular Membranes: Thin structures that encapsulate subcellular structures or ORGANELLES in EUKARYOTIC CELLS. They include a variety of membranes associated with the CELL NUCLEUS; the MITOCHONDRIA; the GOLGI APPARATUS; the ENDOPLASMIC RETICULUM; LYSOSOMES; PLASTIDS; and VACUOLES.Liposomes: Artificial, single or multilaminar vesicles (made from lecithins or other lipids) that are used for the delivery of a variety of biological molecules or molecular complexes to cells, for example, drug delivery and gene transfer. They are also used to study membranes and membrane proteins.Membrane Potentials: The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization).Phospholipids: Lipids containing one or more phosphate groups, particularly those derived from either glycerol (phosphoglycerides see GLYCEROPHOSPHOLIPIDS) or sphingosine (SPHINGOLIPIDS). They are polar lipids that are of great importance for the structure and function of cell membranes and are the most abundant of membrane lipids, although not stored in large amounts in the system.Phosphatidylcholines: Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to a choline moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and choline and 2 moles of fatty acids.Cell Membrane Permeability: A quality of cell membranes which permits the passage of solvents and solutes into and out of cells.Lipid Metabolism: Physiological processes in biosynthesis (anabolism) and degradation (catabolism) of LIPIDS.Cholesterol: The principal sterol of all higher animals, distributed in body tissues, especially the brain and spinal cord, and in animal fats and oils.Temperature: The property of objects that determines the direction of heat flow when they are placed in direct thermal contact. The temperature is the energy of microscopic motions (vibrational and translational) of the particles of atoms.Benzyl Alcohol: A colorless liquid with a sharp burning taste and slight odor. It is used as a local anesthetic and to reduce pain associated with LIDOCAINE injection. Also, it is used in the manufacture of other benzyl compounds, as a pharmaceutic aid, and in perfumery and flavoring.Laurates: Salts and esters of the 12-carbon saturated monocarboxylic acid--lauric acid.Fatty Acids: Organic, monobasic acids derived from hydrocarbons by the equivalent of oxidation of a methyl group to an alcohol, aldehyde, and then acid. Fatty acids are saturated and unsaturated (FATTY ACIDS, UNSATURATED). (Grant & Hackh's Chemical Dictionary, 5th ed)Electron Spin Resonance Spectroscopy: A technique applicable to the wide variety of substances which exhibit paramagnetism because of the magnetic moments of unpaired electrons. The spectra are useful for detection and identification, for determination of electron structure, for study of interactions between molecules, and for measurement of nuclear spins and moments. (From McGraw-Hill Encyclopedia of Science and Technology, 7th edition) Electron nuclear double resonance (ENDOR) spectroscopy is a variant of the technique which can give enhanced resolution. Electron spin resonance analysis can now be used in vivo, including imaging applications such as MAGNETIC RESONANCE IMAGING.2-Naphthylamine: A naphthalene derivative with carcinogenic action.Lipid Peroxidation: Peroxidase catalyzed oxidation of lipids using hydrogen peroxide as an electron acceptor.Lipid A: Lipid A is the biologically active component of lipopolysaccharides. It shows strong endotoxic activity and exhibits immunogenic properties.Basement Membrane: A darkly stained mat-like EXTRACELLULAR MATRIX (ECM) that separates cell layers, such as EPITHELIUM from ENDOTHELIUM or a layer of CONNECTIVE TISSUE. The ECM layer that supports an overlying EPITHELIUM or ENDOTHELIUM is called basal lamina. Basement membrane (BM) can be formed by the fusion of either two adjacent basal laminae or a basal lamina with an adjacent reticular lamina of connective tissue. BM, composed mainly of TYPE IV COLLAGEN; glycoprotein LAMININ; and PROTEOGLYCAN, provides barriers as well as channels between interacting cell layers.1,2-Dipalmitoylphosphatidylcholine: Synthetic phospholipid used in liposomes and lipid bilayers to study biological membranes. It is also a major constituent of PULMONARY SURFACTANTS.Spin Labels: Molecules which contain an atom or a group of atoms exhibiting an unpaired electron spin that can be detected by electron spin resonance spectroscopy and can be bonded to another molecule. (McGraw-Hill Dictionary of Chemical and Technical Terms, 4th ed)Unilamellar Liposomes: Single membrane vesicles, generally made of PHOSPHOLIPIDS.Dimyristoylphosphatidylcholine: A synthetic phospholipid used in liposomes and lipid bilayers for the study of biological membranes.Spectrometry, Fluorescence: Measurement of the intensity and quality of fluorescence.Fluorescent Dyes: Agents that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.Phosphatidylglycerols: A nitrogen-free class of lipids present in animal and particularly plant tissues and composed of one mole of glycerol and 1 or 2 moles of phosphatidic acid. Members of this group differ from one another in the nature of the fatty acids released on hydrolysis.Permeability: Property of membranes and other structures to permit passage of light, heat, gases, liquids, metabolites, and mineral ions.Viscosity: The resistance that a gaseous or liquid system offers to flow when it is subjected to shear stress. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Models, Biological: Theoretical representations that simulate the behavior or activity of biological processes or diseases. For disease models in living animals, DISEASE MODELS, ANIMAL is available. Biological models include the use of mathematical equations, computers, and other electronic equipment.Erythrocytes: Red blood cells. Mature erythrocytes are non-nucleated, biconcave disks containing HEMOGLOBIN whose function is to transport OXYGEN.Diffusion: The tendency of a gas or solute to pass from a point of higher pressure or concentration to a point of lower pressure or concentration and to distribute itself throughout the available space. Diffusion, especially FACILITATED DIFFUSION, is a major mechanism of BIOLOGICAL TRANSPORT.Molecular Conformation: The characteristic three-dimensional shape of a molecule.Protein Binding: The process in which substances, either endogenous or exogenous, bind to proteins, peptides, enzymes, protein precursors, or allied compounds. Specific protein-binding measures are often used as assays in diagnostic assessments.Microscopy, Electron: Microscopy using an electron beam, instead of light, to visualize the sample, thereby allowing much greater magnification. The interactions of ELECTRONS with specimens are used to provide information about the fine structure of that specimen. In TRANSMISSION ELECTRON MICROSCOPY the reactions of the electrons that are transmitted through the specimen are imaged. In SCANNING ELECTRON MICROSCOPY an electron beam falls at a non-normal angle on the specimen and the image is derived from the reactions occurring above the plane of the specimen.Stearates: Salts and esters of the 18-carbon saturated, monocarboxylic acid--stearic acid.Phosphatidylethanolamines: Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to an ethanolamine moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and ethanolamine and 2 moles of fatty acids.Membrane Transport Proteins: Membrane proteins whose primary function is to facilitate the transport of molecules across a biological membrane. Included in this broad category are proteins involved in active transport (BIOLOGICAL TRANSPORT, ACTIVE), facilitated transport and ION CHANNELS.Hydrogen-Ion Concentration: The normality of a solution with respect to HYDROGEN ions; H+. It is related to acidity measurements in most cases by pH = log 1/2[1/(H+)], where (H+) is the hydrogen ion concentration in gram equivalents per liter of solution. (McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Cell Line: Established cell cultures that have the potential to propagate indefinitely.Kinetics: The rate dynamics in chemical or physical systems.Calcium: A basic element found in nearly all organized tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.Microvilli: Minute projections of cell membranes which greatly increase the surface area of the cell.Membrane Microdomains: Detergent-insoluble CELL MEMBRANE components. They are enriched in SPHINGOLIPIDS and CHOLESTEROL and clustered with glycosyl-phosphatidylinositol (GPI)-anchored proteins.Phase Transition: A change of a substance from one form or state to another.Water: A clear, odorless, tasteless liquid that is essential for most animal and plant life and is an excellent solvent for many substances. The chemical formula is hydrogen oxide (H2O). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Hydrophobic and Hydrophilic Interactions: The thermodynamic interaction between a substance and WATER.Fatty Acids, Unsaturated: FATTY ACIDS in which the carbon chain contains one or more double or triple carbon-carbon bonds.Membrane Glycoproteins: Glycoproteins found on the membrane or surface of cells.Alamethicin: A cyclic nonadecapeptide antibiotic that can act as an ionophore and is produced by strains of Trichoderma viride. (From Singleton & Sainsbury, Dictionary of Microbiology and Molecular Biology, 2d ed)Benzyl Alcohols: Alcohols derived from the aryl radical (C6H5CH2-) and defined by C6H5CHOH. The concept includes derivatives with any substituents on the benzene ring.Calorimetry, Differential Scanning: Differential thermal analysis in which the sample compartment of the apparatus is a differential calorimeter, allowing an exact measure of the heat of transition independent of the specific heat, thermal conductivity, and other variables of the sample.Thermodynamics: A rigorously mathematical analysis of energy relationships (heat, work, temperature, and equilibrium). It describes systems whose states are determined by thermal parameters, such as temperature, in addition to mechanical and electromagnetic parameters. (From Hawley's Condensed Chemical Dictionary, 12th ed)Models, Molecular: Models used experimentally or theoretically to study molecular shape, electronic properties, or interactions; includes analogous molecules, computer-generated graphics, and mechanical structures.Mitochondrial Membranes: The two lipoprotein layers in the MITOCHONDRION. The outer membrane encloses the entire mitochondrion and contains channels with TRANSPORT PROTEINS to move molecules and ions in and out of the organelle. The inner membrane folds into cristae and contains many ENZYMES important to cell METABOLISM and energy production (MITOCHONDRIAL ATP SYNTHASE).Protein Transport: The process of moving proteins from one cellular compartment (including extracellular) to another by various sorting and transport mechanisms such as gated transport, protein translocation, and vesicular transport.Escherichia coli: A species of gram-negative, facultatively anaerobic, rod-shaped bacteria (GRAM-NEGATIVE FACULTATIVELY ANAEROBIC RODS) commonly found in the lower part of the intestine of warm-blooded animals. It is usually nonpathogenic, but some strains are known to produce DIARRHEA and pyogenic infections. Pathogenic strains (virotypes) are classified by their specific pathogenic mechanisms such as toxins (ENTEROTOXIGENIC ESCHERICHIA COLI), etc.Cells, Cultured: Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.Ergosterol: A steroid of interest both because its biosynthesis in FUNGI is a target of ANTIFUNGAL AGENTS, notably AZOLES, and because when it is present in SKIN of animals, ULTRAVIOLET RAYS break a bond to result in ERGOCALCIFEROL.Detergents: Purifying or cleansing agents, usually salts of long-chain aliphatic bases or acids, that exert cleansing (oil-dissolving) and antimicrobial effects through a surface action that depends on possessing both hydrophilic and hydrophobic properties.Microscopy, Fluorescence: Microscopy of specimens stained with fluorescent dye (usually fluorescein isothiocyanate) or of naturally fluorescent materials, which emit light when exposed to ultraviolet or blue light. Immunofluorescence microscopy utilizes antibodies that are labeled with fluorescent dye.Sphingomyelins: A class of sphingolipids found largely in the brain and other nervous tissue. They contain phosphocholine or phosphoethanolamine as their polar head group so therefore are the only sphingolipids classified as PHOSPHOLIPIDS.Molecular Sequence Data: Descriptions of specific amino acid, carbohydrate, or nucleotide sequences which have appeared in the published literature and/or are deposited in and maintained by databanks such as GENBANK, European Molecular Biology Laboratory (EMBL), National Biomedical Research Foundation (NBRF), or other sequence repositories.Hemolysis: The destruction of ERYTHROCYTES by many different causal agents such as antibodies, bacteria, chemicals, temperature, and changes in tonicity.Spectroscopy, Fourier Transform Infrared: A spectroscopic technique in which a range of wavelengths is presented simultaneously with an interferometer and the spectrum is mathematically derived from the pattern thus obtained.Models, Chemical: Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.Protein Structure, Tertiary: The level of protein structure in which combinations of secondary protein structures (alpha helices, beta sheets, loop regions, and motifs) pack together to form folded shapes called domains. Disulfide bridges between cysteines in two different parts of the polypeptide chain along with other interactions between the chains play a role in the formation and stabilization of tertiary structure. Small proteins usually consist of only one domain but larger proteins may contain a number of domains connected by segments of polypeptide chain which lack regular secondary structure.Synaptic Membranes: Cell membranes associated with synapses. Both presynaptic and postsynaptic membranes are included along with their integral or tightly associated specializations for the release or reception of transmitters.Bacterial Proteins: Proteins found in any species of bacterium.Electric Conductivity: The ability of a substrate to allow the passage of ELECTRONS.Time Factors: Elements of limited time intervals, contributing to particular results or situations.Ion Channels: Gated, ion-selective glycoproteins that traverse membranes. The stimulus for ION CHANNEL GATING can be due to a variety of stimuli such as LIGANDS, a TRANSMEMBRANE POTENTIAL DIFFERENCE, mechanical deformation or through INTRACELLULAR SIGNALING PEPTIDES AND PROTEINS.Mutation: Any detectable and heritable change in the genetic material that causes a change in the GENOTYPE and which is transmitted to daughter cells and to succeeding generations.beta-Cyclodextrins: Cyclic GLUCANS consisting of seven (7) glucopyranose units linked by 1,4-glycosidic bonds.Protein Conformation: The characteristic 3-dimensional shape of a protein, including the secondary, supersecondary (motifs), tertiary (domains) and quaternary structure of the peptide chain. PROTEIN STRUCTURE, QUATERNARY describes the conformation assumed by multimeric proteins (aggregates of more than one polypeptide chain).Protein Structure, Secondary: The level of protein structure in which regular hydrogen-bond interactions within contiguous stretches of polypeptide chain give rise to alpha helices, beta strands (which align to form beta sheets) or other types of coils. This is the first folding level of protein conformation.Carrier Proteins: Transport proteins that carry specific substances in the blood or across cell membranes.Alcohols: Alkyl compounds containing a hydroxyl group. They are classified according to relation of the carbon atom: primary alcohols, R-CH2OH; secondary alcohols, R2-CHOH; tertiary alcohols, R3-COH. (From Grant & Hackh's Chemical Dictionary, 5th ed)Cold Temperature: An absence of warmth or heat or a temperature notably below an accustomed norm.Amino Acid Sequence: The order of amino acids as they occur in a polypeptide chain. This is referred to as the primary structure of proteins. It is of fundamental importance in determining PROTEIN CONFORMATION.Rabbits: The species Oryctolagus cuniculus, in the family Leporidae, order LAGOMORPHA. Rabbits are born in burrows, furless, and with eyes and ears closed. In contrast with HARES, rabbits have 22 chromosome pairs.Gramicidin: A group of peptide antibiotics from BACILLUS brevis. Gramicidin C or S is a cyclic, ten-amino acid polypeptide and gramicidins A, B, D are linear. Gramicidin is one of the two principal components of TYROTHRICIN.Peptides: Members of the class of compounds composed of AMINO ACIDS joined together by peptide bonds between adjacent amino acids into linear, branched or cyclical structures. OLIGOPEPTIDES are composed of approximately 2-12 amino acids. Polypeptides are composed of approximately 13 or more amino acids. PROTEINS are linear polypeptides that are normally synthesized on RIBOSOMES.Anisotropy: A physical property showing different values in relation to the direction in or along which the measurement is made. The physical property may be with regard to thermal or electric conductivity or light refraction. In crystallography, it describes crystals whose index of refraction varies with the direction of the incident light. It is also called acolotropy and colotropy. The opposite of anisotropy is isotropy wherein the same values characterize the object when measured along axes in all directions.Cattle: Domesticated bovine animals of the genus Bos, usually kept on a farm or ranch and used for the production of meat or dairy products or for heavy labor.Electrochemistry: The study of chemical changes resulting from electrical action and electrical activity resulting from chemical changes.Hexanols: Isomeric forms and derivatives of hexanol (C6H11OH).Phosphatidylserines: Derivatives of phosphatidic acids in which the phosphoric acid is bound in ester linkage to a serine moiety. Complete hydrolysis yields 1 mole of glycerol, phosphoric acid and serine and 2 moles of fatty acids.Receptors, Concanavalin A: Glycoprotein moieties on the surfaces of cell membranes that bind concanavalin A selectively; the number and location of the sites depends on the type and condition of the cell.Static Electricity: The accumulation of an electric charge on a objectBiophysics: The study of PHYSICAL PHENOMENA and PHYSICAL PROCESSES as applied to living things.G(M1) Ganglioside: A specific monosialoganglioside that accumulates abnormally within the nervous system due to a deficiency of GM1-b-galactosidase, resulting in GM1 gangliosidosis.Mitochondria: Semiautonomous, self-reproducing organelles that occur in the cytoplasm of all cells of most, but not all, eukaryotes. Each mitochondrion is surrounded by a double limiting membrane. The inner membrane is highly invaginated, and its projections are called cristae. Mitochondria are the sites of the reactions of oxidative phosphorylation, which result in the formation of ATP. They contain distinctive RIBOSOMES, transfer RNAs (RNA, TRANSFER); AMINO ACYL T RNA SYNTHETASES; and elongation and termination factors. Mitochondria depend upon genes within the nucleus of the cells in which they reside for many essential messenger RNAs (RNA, MESSENGER). Mitochondria are believed to have arisen from aerobic bacteria that established a symbiotic relationship with primitive protoeukaryotes. (King & Stansfield, A Dictionary of Genetics, 4th ed)Biophysical Phenomena: The physical characteristics and processes of biological systems.Cell Fractionation: Techniques to partition various components of the cell into SUBCELLULAR FRACTIONS.Membrane Proteins: Proteins which are found in membranes including cellular and intracellular membranes. They consist of two types, peripheral and integral proteins. They include most membrane-associated enzymes, antigenic proteins, transport proteins, and drug, hormone, and lectin receptors.Lysophosphatidylcholines: Derivatives of PHOSPHATIDYLCHOLINES obtained by their partial hydrolysis which removes one of the fatty acid moieties.Fluorescence: The property of emitting radiation while being irradiated. The radiation emitted is usually of longer wavelength than that incident or absorbed, e.g., a substance can be irradiated with invisible radiation and emit visible light. X-ray fluorescence is used in diagnosis.Norisoprenoids: Thirteen-carbon butene cyclohexene degradation products formed by the cleavage of CAROTENOIDS. They contribute to the flavor of some FRUIT. Ionone should not be confused with the similarly named ionol.Magnetic Resonance Spectroscopy: Spectroscopic method of measuring the magnetic moment of elementary particles such as atomic nuclei, protons or electrons. It is employed in clinical applications such as NMR Tomography (MAGNETIC RESONANCE IMAGING).Cardiolipins: Acidic phospholipids composed of two molecules of phosphatidic acid covalently linked to a molecule of glycerol. They occur primarily in mitochondrial inner membranes and in bacterial plasma membranes. They are the main antigenic components of the Wassermann-type antigen that is used in nontreponemal SYPHILIS SERODIAGNOSIS.Structure-Activity Relationship: The relationship between the chemical structure of a compound and its biological or pharmacological activity. Compounds are often classed together because they have structural characteristics in common including shape, size, stereochemical arrangement, and distribution of functional groups.Freeze Fracturing: Preparation for electron microscopy of minute replicas of exposed surfaces of the cell which have been ruptured in the frozen state. The specimen is frozen, then cleaved under high vacuum at the same temperature. The exposed surface is shadowed with carbon and platinum and coated with carbon to obtain a carbon replica.Microscopy, Atomic Force: A type of scanning probe microscopy in which a probe systematically rides across the surface of a sample being scanned in a raster pattern. The vertical position is recorded as a spring attached to the probe rises and falls in response to peaks and valleys on the surface. These deflections produce a topographic map of the sample.Micelles: Particles consisting of aggregates of molecules held loosely together by secondary bonds. The surface of micelles are usually comprised of amphiphatic compounds that are oriented in a way that minimizes the energy of interaction between the micelle and its environment. Liquids that contain large numbers of suspended micelles are referred to as EMULSIONS.Surface Properties: Characteristics or attributes of the outer boundaries of objects, including molecules.Ketocholesterols: Cholesterol substituted in any position by a keto moiety. The 7-keto isomer inhibits 3-hydroxy-3-methylglutaryl-CoA reductase activity and inhibits cholesterol uptake in the coronary arteries and aorta in vitro.Electrophoresis, Polyacrylamide Gel: Electrophoresis in which a polyacrylamide gel is used as the diffusion medium.Solubility: The ability of a substance to be dissolved, i.e. to form a solution with another substance. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Tenuazonic Acid: 3-Acetyl-5-sec-butyl-4-hydroxy-3-pyrrolin-2-one. A metabolite found in a strain of the fungus Alternaria tenuis Auct. which functions as an antibiotic with antiviral and antineoplastic properties, and may also act as a mycotoxin.Binding Sites: The parts of a macromolecule that directly participate in its specific combination with another molecule.Liver: A large lobed glandular organ in the abdomen of vertebrates that is responsible for detoxification, metabolism, synthesis and storage of various substances.Microscopy, Confocal: A light microscopic technique in which only a small spot is illuminated and observed at a time. An image is constructed through point-by-point scanning of the field in this manner. Light sources may be conventional or laser, and fluorescence or transmitted observations are possible.Sodium-Potassium-Exchanging ATPase: An enzyme that catalyzes the active transport system of sodium and potassium ions across the cell wall. Sodium and potassium ions are closely coupled with membrane ATPase which undergoes phosphorylation and dephosphorylation, thereby providing energy for transport of these ions against concentration gradients.Nisin: A 34-amino acid polypeptide antibiotic produced by Streptococcus lactis. It has been used as a food preservative in canned fruits and vegetables, and cheese.Endoplasmic Reticulum: A system of cisternae in the CYTOPLASM of many cells. In places the endoplasmic reticulum is continuous with the plasma membrane (CELL MEMBRANE) or outer membrane of the nuclear envelope. If the outer surfaces of the endoplasmic reticulum membranes are coated with ribosomes, the endoplasmic reticulum is said to be rough-surfaced (ENDOPLASMIC RETICULUM, ROUGH); otherwise it is said to be smooth-surfaced (ENDOPLASMIC RETICULUM, SMOOTH). (King & Stansfield, A Dictionary of Genetics, 4th ed)Fatty Acid Desaturases: A family of enzymes that catalyze the stereoselective, regioselective, or chemoselective syn-dehydrogenation reactions. They function by a mechanism that is linked directly to reduction of molecular OXYGEN.Fluoresceins: A family of spiro(isobenzofuran-1(3H),9'-(9H)xanthen)-3-one derivatives. These are used as dyes, as indicators for various metals, and as fluorescent labels in immunoassays.Sterols: Steroids with a hydroxyl group at C-3 and most of the skeleton of cholestane. Additional carbon atoms may be present in the side chain. (IUPAC Steroid Nomenclature, 1987)Signal Transduction: The intracellular transfer of information (biological activation/inhibition) through a signal pathway. In each signal transduction system, an activation/inhibition signal from a biologically active molecule (hormone, neurotransmitter) is mediated via the coupling of a receptor/enzyme to a second messenger system or to an ion channel. Signal transduction plays an important role in activating cellular functions, cell differentiation, and cell proliferation. Examples of signal transduction systems are the GAMMA-AMINOBUTYRIC ACID-postsynaptic receptor-calcium ion channel system, the receptor-mediated T-cell activation pathway, and the receptor-mediated activation of phospholipases. Those coupled to membrane depolarization or intracellular release of calcium include the receptor-mediated activation of cytotoxic functions in granulocytes and the synaptic potentiation of protein kinase activation. Some signal transduction pathways may be part of larger signal transduction pathways; for example, protein kinase activation is part of the platelet activation signal pathway.Extraembryonic Membranes: The thin layers of tissue that surround the developing embryo. There are four extra-embryonic membranes commonly found in VERTEBRATES, such as REPTILES; BIRDS; and MAMMALS. They are the YOLK SAC, the ALLANTOIS, the AMNION, and the CHORION. These membranes provide protection and means to transport nutrients and wastes.Molecular Structure: The location of the atoms, groups or ions relative to one another in a molecule, as well as the number, type and location of covalent bonds.Potassium: An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.Golgi Apparatus: A stack of flattened vesicles that functions in posttranslational processing and sorting of proteins, receiving them from the rough ENDOPLASMIC RETICULUM and directing them to secretory vesicles, LYSOSOMES, or the CELL MEMBRANE. The movement of proteins takes place by transfer vesicles that bud off from the rough endoplasmic reticulum or Golgi apparatus and fuse with the Golgi, lysosomes or cell membrane. (From Glick, Glossary of Biochemistry and Molecular Biology, 1990)Dose-Response Relationship, Drug: The relationship between the dose of an administered drug and the response of the organism to the drug.Porosity: Condition of having pores or open spaces. This often refers to bones, bone implants, or bone cements, but can refer to the porous state of any solid substance.Pyrenes: A group of condensed ring hydrocarbons.Rats, Inbred Strains: Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.Recombinant Fusion Proteins: Recombinant proteins produced by the GENETIC TRANSLATION of fused genes formed by the combination of NUCLEIC ACID REGULATORY SEQUENCES of one or more genes with the protein coding sequences of one or more genes.Molecular Weight: The sum of the weight of all the atoms in a molecule.Lipid Peroxides: Peroxides produced in the presence of a free radical by the oxidation of unsaturated fatty acids in the cell in the presence of molecular oxygen. The formation of lipid peroxides results in the destruction of the original lipid leading to the loss of integrity of the membranes. They therefore cause a variety of toxic effects in vivo and their formation is considered a pathological process in biological systems. Their formation can be inhibited by antioxidants, such as vitamin E, structural separation or low oxygen tension.Oxidation-Reduction: A chemical reaction in which an electron is transferred from one molecule to another. The electron-donating molecule is the reducing agent or reductant; the electron-accepting molecule is the oxidizing agent or oxidant. Reducing and oxidizing agents function as conjugate reductant-oxidant pairs or redox pairs (Lehninger, Principles of Biochemistry, 1982, p471).Octoxynol: Nonionic surfactant mixtures varying in the number of repeating ethoxy (oxy-1,2-ethanediyl) groups. They are used as detergents, emulsifiers, wetting agents, defoaming agents, etc. Octoxynol-9, the compound with 9 repeating ethoxy groups, is a spermatocide.Rats, Wistar: A strain of albino rat developed at the Wistar Institute that has spread widely at other institutions. This has markedly diluted the original strain.Abetalipoproteinemia: An autosomal recessive disorder of lipid metabolism. It is caused by mutation of the microsomal triglyceride transfer protein that catalyzes the transport of lipids (TRIGLYCERIDES; CHOLESTEROL ESTERS; PHOSPHOLIPIDS) and is required in the secretion of BETA-LIPOPROTEINS (low density lipoproteins or LDL). Features include defective intestinal lipid absorption, very low serum cholesterol level, and near absent LDL.Tetraphenylborate: An anionic compound that is used as a reagent for determination of potassium, ammonium, rubidium, and cesium ions. It also uncouples oxidative phosphorylation and forms complexes with biological materials, and is used in biological assays.Porins: Porins are protein molecules that were originally found in the outer membrane of GRAM-NEGATIVE BACTERIA and that form multi-meric channels for the passive DIFFUSION of WATER; IONS; or other small molecules. Porins are present in bacterial CELL WALLS, as well as in plant, fungal, mammalian and other vertebrate CELL MEMBRANES and MITOCHONDRIAL MEMBRANES.Sodium: A member of the alkali group of metals. It has the atomic symbol Na, atomic number 11, and atomic weight 23.Oleic Acids: A group of fatty acids that contain 18 carbon atoms and a double bond at the omega 9 carbon.Cytoplasm: The part of a cell that contains the CYTOSOL and small structures excluding the CELL NUCLEUS; MITOCHONDRIA; and large VACUOLES. (Glick, Glossary of Biochemistry and Molecular Biology, 1990)Cations: Positively charged atoms, radicals or groups of atoms which travel to the cathode or negative pole during electrolysis.Biological Transport, Active: The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.Mathematics: The deductive study of shape, quantity, and dependence. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Cyclic N-Oxides: Heterocyclic compounds in which an oxygen is attached to a cyclic nitrogen.Recombinant Proteins: Proteins prepared by recombinant DNA technology.Adsorption: The adhesion of gases, liquids, or dissolved solids onto a surface. It includes adsorptive phenomena of bacteria and viruses onto surfaces as well. ABSORPTION into the substance may follow but not necessarily.Adenosine Triphosphate: An adenine nucleotide containing three phosphate groups esterified to the sugar moiety. In addition to its crucial roles in metabolism adenosine triphosphate is a neurotransmitter.Carboprost: A nonsteroidal abortifacient agent that is effective in both the first and second trimesters of PREGNANCY.Biological Transport: The movement of materials (including biochemical substances and drugs) through a biological system at the cellular level. The transport can be across cell membranes and epithelial layers. It also can occur within intracellular compartments and extracellular compartments.Nystatin: Macrolide antifungal antibiotic complex produced by Streptomyces noursei, S. aureus, and other Streptomyces species. The biologically active components of the complex are nystatin A1, A2, and A3.Cell Membrane Structures: Structures which are part of the CELL MEMBRANE or have cell membrane as a major part of their structure.Circular Dichroism: A change from planar to elliptic polarization when an initially plane-polarized light wave traverses an optically active medium. (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Endocytosis: Cellular uptake of extracellular materials within membrane-limited vacuoles or microvesicles. ENDOSOMES play a central role in endocytosis.Cricetinae: A subfamily in the family MURIDAE, comprising the hamsters. Four of the more common genera are Cricetus, CRICETULUS; MESOCRICETUS; and PHODOPUS.Rats, Sprague-Dawley: A strain of albino rat used widely for experimental purposes because of its calmness and ease of handling. It was developed by the Sprague-Dawley Animal Company.Surface Tension: The force acting on the surface of a liquid, tending to minimize the area of the surface. (From McGraw-Hill Dictionary of Scientific and Technical Terms, 6th ed)Melitten: Basic polypeptide from the venom of the honey bee (Apis mellifera). It contains 26 amino acids, has cytolytic properties, causes contracture of muscle, releases histamine, and disrupts surface tension, probably due to lysis of cell and mitochondrial membranes.Concanavalin A: A MANNOSE/GLUCOSE binding lectin isolated from the jack bean (Canavalia ensiformis). It is a potent mitogen used to stimulate cell proliferation in lymphocytes, primarily T-lymphocyte, cultures.Ca(2+) Mg(2+)-ATPaseOleic Acid: An unsaturated fatty acid that is the most widely distributed and abundant fatty acid in nature. It is used commercially in the preparation of oleates and lotions, and as a pharmaceutical solvent. (Stedman, 26th ed)Protons: Stable elementary particles having the smallest known positive charge, found in the nuclei of all elements. The proton mass is less than that of a neutron. A proton is the nucleus of the light hydrogen atom, i.e., the hydrogen ion.Ions: An atom or group of atoms that have a positive or negative electric charge due to a gain (negative charge) or loss (positive charge) of one or more electrons. Atoms with a positive charge are known as CATIONS; those with a negative charge are ANIONS.Proteolipids: Protein-lipid combinations abundant in brain tissue, but also present in a wide variety of animal and plant tissues. In contrast to lipoproteins, they are insoluble in water, but soluble in a chloroform-methanol mixture. The protein moiety has a high content of hydrophobic amino acids. The associated lipids consist of a mixture of GLYCEROPHOSPHATES; CEREBROSIDES; and SULFOGLYCOSPHINGOLIPIDS; while lipoproteins contain PHOSPHOLIPIDS; CHOLESTEROL; and TRIGLYCERIDES.Cytochalasin B: A cytotoxic member of the CYTOCHALASINS.Electric Capacitance: The ability of a substrate to retain an electrical charge.Adaptation, Physiological: The non-genetic biological changes of an organism in response to challenges in its ENVIRONMENT.1-Butanol: A four carbon linear hydrocarbon that has a hydroxy group at position 1.Polyethylene Glycols: Polymers of ETHYLENE OXIDE and water, and their ethers. They vary in consistency from liquid to solid depending on the molecular weight indicated by a number following the name. They are used as SURFACTANTS, dispersing agents, solvents, ointment and suppository bases, vehicles, and tablet excipients. Some specific groups are NONOXYNOLS, OCTOXYNOLS, and POLOXAMERS.Mitochondria, Liver: Mitochondria in hepatocytes. As in all mitochondria, there are an outer membrane and an inner membrane, together creating two separate mitochondrial compartments: the internal matrix space and a much narrower intermembrane space. In the liver mitochondrion, an estimated 67% of the total mitochondrial proteins is located in the matrix. (From Alberts et al., Molecular Biology of the Cell, 2d ed, p343-4)Spermatozoa: Mature male germ cells derived from SPERMATIDS. As spermatids move toward the lumen of the SEMINIFEROUS TUBULES, they undergo extensive structural changes including the loss of cytoplasm, condensation of CHROMATIN into the SPERM HEAD, formation of the ACROSOME cap, the SPERM MIDPIECE and the SPERM TAIL that provides motility.Swine: Any of various animals that constitute the family Suidae and comprise stout-bodied, short-legged omnivorous mammals with thick skin, usually covered with coarse bristles, a rather long mobile snout, and small tail. Included are the genera Babyrousa, Phacochoerus (wart hogs), and Sus, the latter containing the domestic pig (see SUS SCROFA).Computer Simulation: Computer-based representation of physical systems and phenomena such as chemical processes.Submitochondrial Particles: The various filaments, granules, tubules or other inclusions within mitochondria.Base Sequence: The sequence of PURINES and PYRIMIDINES in nucleic acids and polynucleotides. It is also called nucleotide sequence.Sequence Homology, Amino Acid: The degree of similarity between sequences of amino acids. This information is useful for the analyzing genetic relatedness of proteins and species.Peptide Fragments: Partial proteins formed by partial hydrolysis of complete proteins or generated through PROTEIN ENGINEERING techniques.Purple Membrane: Functionally and structurally differentiated, purple-pigmented regions of the cytoplasmic membrane of some strains of Halobacterium halobium. The membrane develops under anaerobic conditions and is made almost entirely of the purple pigment BACTERIORHODOPSINS. (From Singleton & Sainsbury Dictionary of Microbiology and Molecular Biology, 2d ed)17-Hydroxycorticosteroids: A group of hydroxycorticosteroids bearing a hydroxy group at the 17-position. Urinary excretion of these compounds is used as an index of adrenal function. They are used systemically in the free alcohol form, but with esterification of the hydroxy groups, topical effectiveness is increased.Osmosis: Tendency of fluids (e.g., water) to move from the less concentrated to the more concentrated side of a semipermeable membrane.Hot Temperature: Presence of warmth or heat or a temperature notably higher than an accustomed norm.Membrane Potential, Mitochondrial: The voltage difference, normally maintained at approximately -180mV, across the INNER MITOCHONDRIAL MEMBRANE, by a net movement of positive charge across the membrane. It is a major component of the PROTON MOTIVE FORCE in MITOCHONDRIA used to drive the synthesis of ATP.Anions: Negatively charged atoms, radicals or groups of atoms which travel to the anode or positive pole during electrolysis.Surface-Active Agents: Agents that modify interfacial tension of water; usually substances that have one lipophilic and one hydrophilic group in the molecule; includes soaps, detergents, emulsifiers, dispersing and wetting agents, and several groups of antiseptics.Escherichia coli Proteins: Proteins obtained from ESCHERICHIA COLI.Cytosol: Intracellular fluid from the cytoplasm after removal of ORGANELLES and other insoluble cytoplasmic components.Oxidative Stress: A disturbance in the prooxidant-antioxidant balance in favor of the former, leading to potential damage. Indicators of oxidative stress include damaged DNA bases, protein oxidation products, and lipid peroxidation products (Sies, Oxidative Stress, 1991, pxv-xvi).Electrophysiology: The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.Fluorescent Antibody Technique: Test for tissue antigen using either a direct method, by conjugation of antibody with fluorescent dye (FLUORESCENT ANTIBODY TECHNIQUE, DIRECT) or an indirect method, by formation of antigen-antibody complex which is then labeled with fluorescein-conjugated anti-immunoglobulin antibody (FLUORESCENT ANTIBODY TECHNIQUE, INDIRECT). The tissue is then examined by fluorescence microscopy.Molecular Dynamics Simulation: A computer simulation developed to study the motion of molecules over a period of time.Anti-Bacterial Agents: Substances that reduce the growth or reproduction of BACTERIA.Calorimetry: The measurement of the quantity of heat involved in various processes, such as chemical reactions, changes of state, and formations of solutions, or in the determination of the heat capacities of substances. The fundamental unit of measurement is the joule or the calorie (4.184 joules). (McGraw-Hill Dictionary of Scientific and Technical Terms, 4th ed)Cloning, Molecular: The insertion of recombinant DNA molecules from prokaryotic and/or eukaryotic sources into a replicating vehicle, such as a plasmid or virus vector, and the introduction of the resultant hybrid molecules into recipient cells without altering the viability of those cells.Brain: The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.Light: That portion of the electromagnetic spectrum in the visible, ultraviolet, and infrared range.
The lipid bilayer gives fluidity and elasticity to membrane. Small amounts of carbohydrates are also found in cell membrane.The ... 1935 - Hugh Davson and James Danielli proposed that lipid membranes are layers composed by proteins and lipids with pore-like ... Cell membrane proteins and glycoproteins do not exist as single elements of the lipid membrane, as first proposed by Singer and ... Lipid rafts are membrane nanometric platforms with a particular lipid and protein composition that laterally diffuse, ...
... s such as cholesterol decrease membrane fluidity. Similar to lipids, steroids are highly concentrated energy stores. ... are important components of cell membranes which alter membrane fluidity, and many steroids are signaling molecules which ... the latter is a structural component of cell membranes which helps determine the fluidity of cell membranes and is a principal ... Examples include the dietary lipid cholesterol, the sex hormones estradiol and testosterone and the anti-inflammatory drug ...
Electronic microscope Fluorescence Cell membrane Fluidity Lipid Raft Gregorio Weber Parasassi, T; Gratton E.; Levi M. (1997). " ... It is used to investigate membrane qualities of the phospholipid bilayers of cell membranes. One of its most important ... inadequate to observe the membrane lipid bilayer because of their interaction with other compounds within the membrane lipid ... Laurdan was first applied to study membrane fluidity of live cells with a 2-Photon fluorescence microscope in 1994 and it was ...
... and increased fluidity of membrane lipids. Other indirect or slower heat injuries involve inactivation of enzymes in ... and measurement of solute leakage from tissue can be used to estimate damage to membranes. Since membrane thermostability is ... C) Membrane thermostability Although resistance to high temperatures involves several complex tolerance and avoidance ... and membrane stability. Studies have found tremendous variation within and between species, thus this will help to breed heat ...
... is the adaptation of the cell membrane lipid composition to keep the adequate membrane fluidity. The ... and proper separation of membranes during cell division. A fundamental biophysical determinant of membrane fluidity is the ... Regulating membrane fluidity is especially important in poikilothermic organisms such as bacteria, fungi, protists, plants, ... Sinensky M (February 1974). "Homeoviscous adaptation--a homeostatic process that regulates the viscosity of membrane lipids in ...
Majority of the membrane is composed of phospholipids, which exhibit fluidity like oil. The phospholids are not just stationary ... Studies on lipid organization in model and biological membranes". Cellular & Molecular Biology Letters. 8 (1): 147-159. PMID ... According to the Fluid Mosaic Model, in contrast to other models, the cell membrane is composed of a single lipid bilayer which ... Earlier descriptions of the cell membrane had serious inconsistencies with observed properties of the lipid bilayer. ...
Their amphipathic nature drives the formation of the lipid bilayer structure of membranes. The cell membrane seen under the ... These alterations result in changes in membrane fluidity and permeability. These processes along with the accumulation of lipid ... These compounds are key components of the membranes of muscles and nerves. Phosphatidates Phosphatidates are lipids in which ... incorporation into membranes, functions, and involvement in neurological disorders". Chemistry and physics of lipids. 106 (1): ...
Increased PUFA concentrations decrease the membrane fluidity and help the bacterium thrive in the cold temperatures. The exact ... These categories were created from an evaluation of the 16s rRNA sequences as well as a comparison of membrane lipid ... Group 1 species contain a notably higher percentage of polyunsaturated fatty acids integrated in their membranes. Samples of S ... "Eicosapentaenoic acid plays a beneficial role in membrane organization and cell division of a cold-adapted bacterium, ...
... motions include the rates of translational diffusion of lipids in bilayer membranes as well as the rates of trans membrane ... provided some of the earliest evidence for the fluidity of biological membranes. His recent research was concerned with the ... These studies range all the way from lipid monolayers at the air-water interface to the regions of membrane-membrane contact ... An important contribution was the introduction of supported lipid bilayers to mimic cell surfaces. For example, this system was ...
... s protect against cardiovascular disease by providing more membrane fluidity than saturated fats, but they ... The saturation index (SI) of the same membranes was inversely associated with breast cancer risk. Monounsaturated fats and low ... "Feinberg School > Nutrition > Nutrition Fact Sheet: Lipids". Northwestern University. Archived from the original on 2011-07-20 ... "Erythrocyte Membrane Fatty Acids and Subsequent Breast Cancer: a Prospective Italian Study". JNCL. 93 (14): 1088-95. doi: ...
... that is provokes the reduction of membrane viscosity and the increase of its fluidity, increases lipid-protein ratio. Modulates ... Modulates the receptor complexes of the brain membranes, i.e. benzodiazepine, GABA, acetylcholine receptors by increasing their ... Emoxypine effectively inhibits free radical oxidation of biomembrane lipids, reacts to peroxide radicals of lipids primary and ... Stabilizes biomembranes, i.e. membrane structures of blood cells - erythrocytes and thrombocytes during their haemolysis or ...
... s are a class of lipids that are a major component of all cell membranes. They can form lipid bilayers because of ... Sterols contribute to membrane fluidity by hindering the packing together of phospholipids. However, this model has now been ... so proteins and lipid molecules are then free to diffuse laterally through the lipid matrix and migrate over the membrane. ... Lipid bilayers occur when hydrophobic tails line up against one another, forming a membrane of hydrophilic heads on both sides ...
... loss of DHA from the retina-probably caused by peroxidative degradation-and changes in retinal membrane fluidity. The treatment ... Visual changes-Photoreceptor outer segment membranes have a very high concentration of polyunsaturated fatty acids (PUFA's) and ... lipid-soluble antioxidant in vivo. After 12 months of experimental vitamin E deficiency in rats, visual function was absent or ... It causes nerve problems due to poor conduction of electrical impulses along nerves due to changes in nerve membrane structure ...
Lipid peroxidation is known to destroy membranes of both cells and membrane-bound organelles. The derivative of 7DHC that is ... It is a structural component of the cell membrane, such that it provides structure and regulates the fluidity of the ... that float within the cell membrane, and play a role in the regulation of membrane function. Lipid rafts are more ordered or ... In addition, a lack of cholesterol contributes to the increased fluidity of the cell membrane, and may cause abnormal granule ...
Lipids forming the thylakoid membranes, richest in high-fluidity linolenic acid are synthesized in a complex pathway involving ... synthesize new membrane lipids, and properly target proteins to the correct membrane system. The outer membrane, plasma ... The thylakoid lipid bilayer shares characteristic features with prokaryotic membranes and the inner chloroplast membrane. For ... YashRoy, R.C. (1987). "13C NMR studies of lipid fatty-acyl chains of chloroplast membranes". Indian Journal of Biochemistry and ...
Unsaturated chains have a lower melting point, hence these molecules increase the fluidity of cell membranes. Although both ... to maintain greater membrane fluidity (and functionality) at the lower temperatures. Iodine value - a chemical analysis method ... the more vulnerable it is to lipid peroxidation (rancidity). Antioxidants can protect unsaturated fat from lipid peroxidation. ... Studies on the cell membranes of mammals and reptiles discovered that mammalian cell membranes are composed of a higher ...
Alterations occur in Lipid A. Salmonella species reduce the fluidity of their outer membrane by increasing hydrophobic ... In contrast, the outer part of the membranes of plants and mammals is mainly composed of lipids without any net charges since ... This amphipathicity of the antimicrobial peptides allows them to partition into the membrane lipid bilayer. The ability to ... It's well known that cholesterol is normally widely distributed in the mammalian cell membranes as a membrane stabilizing ...
... with minimal effects on the biophysical properties of the membrane. Molecular interactions with neighboring membrane lipids ... Schroeder F (November 1978). "Differences in fluidity between bilayer halves of tumour cell plasma membranes". Nature. 276 ( ... For example, it was used to help establish the existence of a "fluidity gradient" across the membrane bilayer of some tumor ... α-Parinaric acid is also used as a chromophore to study interactions between membrane proteins and lipids. Because of the ...
... study the flexibility gradient of membrane lipids to understand membrane fluidity conditions at different depths of their lipid ... Spin labelled fatty acids have been extensively used to understand dynamic organization of lipids in bio-membranes and membrane ... Yashroy, R. C. (1990). "Magnetic resonance studies of dynamic organisation of lipids in chloroplast membranes". Journal of ... Spin labels are normally used as tools for probing proteins or biological membrane-local dynamics using electron paramagnetic ...
Thus membranes are fluidized only by large quantities of anaesthetics, but there are no changes in membrane fluidity when ... Thus, some membrane proteins are proposed to be sensitive to their lipid environment. A slightly different detailed molecular ... However, changes in membrane density and fluidity in the presence of clinical concentrations of general anaesthetics are so ... These lateral stresses are rather large and vary with depth within the membrane. According to the modern lipid hypothesis a ...
The changes in membrane lipid composition lead to a higher membrane fluidity, thus keeping the membrane from "freezing" at low ... In plants and microbes, changes in the lipid composition of cell membranes have been linked to cold tolerance. The enhanced ... The "lipid hypothesis of osteoporosis" postulates that lipids involved in causing heart disease also contribute to causing ... The lipid hypothesis is a medical theory postulating a link between blood cholesterol levels and occurrence of heart disease. A ...
In 1974, the effects of temperature on membrane behavior had led to the proposal of "clusters of lipids" in membranes and by ... influencing membrane fluidity and membrane protein trafficking, and regulating neurotransmission and receptor trafficking. ... In the plasma membrane, one approach of compartmentalization utilizes lipid rafts. One reasonable way to consider lipid rafts ... "Lipid Rafts, Signalling and the Cytoskeleton" at University of Edinburgh Satyajit Mayor's seminar: "Membrane Rafts" Lipid Rafts ...
The phospholipid displacement changes in fluidity, and the cellular contents leak out. The presence of anionic lipids or ... The mechanism of pardaxin is dependent on the membrane composition. Pardaxin significantly disrupts lipid bilayers composed of ... This makes it easier for it to interact with anionic membranes, such as those in tumor cells, which are inherently more acidic ... "Membrane Composition Determines Pardaxin's Mechanism of Lipid Bilayer Disruption". Biophysical Journal. 83 (2): 1004-1013. PMC ...
Among other things, arachidonic acid helps to maintain hippocampal cell membrane fluidity.[23] It also helps protect the brain ... blood lipid levels, and tissue fatty acid composition in humans". Lipids. 32 (4): 427-33. doi:10.1007/s11745-997-0056-6. PMID ... of membranes of the body's cells, and is abundant in the brain, muscles, and liver. Skeletal muscle is an especially active ... "Arachidonic acid preserves hippocampal neuron membrane fluidity in senescent rats". Neurobiology of Aging. 28 (8): 1179-1186. ...
... fluidity. Plant thylakoid membranes maintain high fluidity, even at relatively cold environmental temperatures, due the ... Membrane lipids also form a matrix in which membrane proteins reside. Historically lipids were thought to merely serve a ... lipid bilayer). The three major classes of membrane lipids are phospholipids, glycolipids, and cholesterol. Lipids are ... Non-bilayer forming lipid like monogalactosyl diglyceride (MGDG) predominates the bulk lipids in thylakoid membranes, which ...
Cholesterol is required to build and maintain cell membranes; it regulates membrane fluidity over a wide range of temperatures ... assisting in the formation of lipid rafts in the plasma membrane. It also reduces the permeability of the plasma membrane to ... Haines TH (2001). "Do sterols reduce proton and sodium leaks through lipid bilayers?". Prog. Lipid Res. 40 (4): 299-324. doi: ... මූලික ලිපියන්: hypercholesterolemia සහ lipid hypothesis. According to the lipid hypothesis, abnormally high cholesterol levels ...
Cells maintain membrane fluidity by regulating lipid saturation, but the molecular mechanisms of this homeoviscous adaptation ... Our data challenge the prevailing hypothesis that membrane fluidity serves as the measured variable for regulating lipid ... Rather, we show that Mga2 senses the molecular lipid-packing density in a defined region of the membrane. Our findings suggest ... and configuration of double bonds in lipid acyl chains, and provide insights into the molecular rules of membrane adaptation. ...
Cell Membrane*/ultrastructure. *Crystallization. *Erythrocytes/ultrastructure. *Escherichia coli/ultrastructure. *Lipids*/ ... Phase transitions and fluidity characteristics of lipids and cell membranes.. Chapman D. ...
Role of lindane in membranes. Effects on membrane fluidity and activity of membrane-bound proteins Biosci Rep (June, 1994) ... Lindane-induced modifications to membrane lipid structure: Effect on membrane fluidity after subchronic treament M. T. ... resulted in an altered lipid pattern in rat ventral prostate membranes. An increase of membrane fluidity was also observed ... Lindane-induced modifications to membrane lipid structure: Effect on membrane fluidity after subchronic treament. Biosci Rep 1 ...
In this study, organisms with more complex membranes, namely, archaea, did not maintain high growth rates upon exposure to ... Role of Alcohols in Growth, Lipid Composition, and Membrane Fluidity of Yeasts, Bacteria, and Archaea. Sarah Huffer, Melinda E ... Increased membrane fluidity, which causes cofactor leakage and loss of membrane potential, has long been documented as a cause ... Role of Alcohols in Growth, Lipid Composition, and Membrane Fluidity of Yeasts, Bacteria, and Archaea ...
... role of thyroid hormones status in animals in modulation of Na+-Pitransport activity in intestinal brush border membrane ... Brasitus TA, Dudeja PK: Effect of Hypothyroidsm on the lipid composition and fluidity of rat colonic apical plasma membranes. ... Spector AA, Yorek MA: Membrane lipid composition and cellular function. J Lipid Res 26: 1015-1035, 1985PubMedGoogle Scholar ... Thyroid hormones increase Na+-Pi co-transport activity in intestinal brush border membrane: Role of membrane lipid composition ...
... decrease of nuclear membranes induced by low calcium magnesium modulation of nuclear membrane lipid fluidity by the membrane ... Expansion and apparent fluidity decrease of nuclear membranes induced by low Ca/Mg. Modulation of nuclear membrane lipid ... C only in expanded nuclear membranes. In contrast to the nuclear membrane-bound lipids, free lipids extracted from the nuclei ... decrease of nuclear membranes induced by low calcium magnesium modulation of nuclear membrane lipid fluidity by the membrane ...
Effects of growth temperature and lipophilic carbon sources on the fatty acid composition and membrane lipid fluidity of ... indicating that the fluidity of their outer and cytoplasmic membranes fell as growth temperature increased. The liposomes ... Effects of phospho lipid fatty acid composition and membrane fluidity on the activity of bovine brain phospho lipid exchange ... Does the fluidity of the lipid environment modulate membrane-bound acetylcholinesterase? Effects of temperature, membrane ...
Investigation into the fluidity of lipopolysaccharide and free lipid A membrane systems by Fourier-transform infrared ... The outer membranes of Brucella spp. are not barriers to hydrophobic permeants. J. Bacteriol.175:5273-5275. ... With regard to the acyl chain fluidity and the lipid A analyses, the good correspondence between the 2°C difference in the Tc ... Although the lipid A of serotype O:8 was not examined, Aussel et al. (2) found hexa-, penta-, and tetraacyl lipid A in the LPS ...
The extent of this diffusion relies on the structure of both the membrane and the diffusing species. Artificial lipid membranes ... STRUCTURE AND FLUIDITY OF LIPID MEMBRANES ON POLYMER SUPPORTS. Author:. GRIFFIN, KAITLYN RENEE. Issue Date:. 2016 Publisher:. ... The extent of this diffusion relies on the structure of both the membrane and the diffusing species. Artificial lipid membranes ... Diffusion across a lipid membrane can occur spontaneously or be facilitated by integral membrane proteins. ...
The lipids in the viral membrane are noticeably less fluid than the lipids in the membrane of the cells in which the virus was ... This difference in fluidity is not due simply to differences in lipid composition but instead appears to be the result of the ... The possible role of this viral protein-mediated alteration of the physical statr of membrane lipids in the maturation of ... interaction of the viral proteins with the membrane lipids. This conclusion seems clear because (i) the viral lipids are more ...
Membrane lipids are principally of two types, phospholipids and sterols (generally cholesterol). Both types share the defining ... characteristic of lipids-they dissolve readily in organic solvents-but in addition they both have a region that is attracted to ... Membrane fluidity. One of the triumphs of cell biology during the decade from 1965 to 1975 was the recognition of the cell ... is basic to the role of lipids as building blocks of cellular membranes. Phospholipid molecules have a head (often of glycerol ...
... on the fluidity of phosphatidylcholine vesicles. Changes in fluidity were assessed by changes in anisotropy values calculated ... These results suggest the possibility that these peptides may alter the fluidity of cell membranes by a direct action on the ... Lipid Bilayers / metabolism * Liposomes / metabolism* * Membrane Fluidity / drug effects* * Peptides / metabolism * Peptides / ... Angiotensin II and related peptides alter liposomal membrane fluidity Biochem Mol Biol Int. 1998 Jan;44(1):203-9. doi: 10.1080/ ...
The extent of this diffusion relies on the structure of both the membrane and the diffusing species. Artificial lipid membranes ... The extent of this diffusion relies on the structure of both the membrane and the diffusing species. Artificial lipid membranes ... Diffusion across a lipid membrane can occur spontaneously or be facilitated by integral membrane proteins. ... Diffusion across a lipid membrane can occur spontaneously or be facilitated by integral membrane proteins. ...
The extent of this diffusion relies on the structure of both the membrane and the diffusing species. Artificial lipid membranes ... Diffusion across a lipid membrane can occur spontaneously or be facilitated by integral membrane proteins. ... Cell membranes are composed primarily of amphipathic lipids either in a single circular layer or as a bilayer in which all of ... Modification of the SU-8 3050 surface to enhance both membrane stability and fluidity are being investigated while not ...
... affect a wide variety of membrane and cellular activities 1-5greatly stimulated interest in the study of membrane fluidity. It ... C.J. Livingstone and D. Schachter, Lipid dynamics and lipid-protein interactions in rat hepatocyte plasma membranes, J. Biol. ... J.R. Riordan, Plasma membrane Mg2+ ATPase activity is inversely related to lipid fluidity in: Membrane Fluidity. Biophysical ... Interconnection of activities and membrane lipid fluidity in: Membrane Fluidity. Biophysical and Cellular Regulation, M. Kates ...
This study proposes a new anti-viral strategy to directly suppress the fluidity of lipid bilayer membranes, inhibiting the ... Lipid composition and fluidity of the human immunodeficiency virus envelope and host plasma membranes ... The fluidity of the membrane results from anisotropic rotation of phopholipid acyl chains and flip-flop movement of membrane ... The kinetics of C-2 virus envelope fluidity (Figure 6B) were somewhat different from those of plasma membrane fluidity (Figure ...
OS increases the cholesterol content in EC membranes, which results in decreased membrane fluidity (21). Such alterations of ... Integrin α5 Activity Is Regulated by Membrane Fluidity and Cholesterol Content.. As membrane fluidity affects the mobility of ... in turn altering membrane fluidity (21), we next investigated the involvement of membrane fluidity in flow regulation of ... OS promotes integrin α5 translocation to lipid rafts through alteration of membrane fluidity. HUVECs were treated with β-CD (5 ...
Discrete lipid domains with differing composition, and thus membrane fluidity, can coexist in model lipid membranes; this can ... membrane fluidity refers to the viscosity of the lipid bilayer of a cell membrane or a synthetic lipid membrane. Lipid packing ... Also, a narrow annular lipid shell of membrane lipids in contact with integral membrane proteins have low fluidity compared to ... Membrane fluidity can be affected by a number of factors. One way to increase membrane fluidity is to heat up the membrane. ...
... presumably by maintaining membrane fluidity. The fluidity of isolated cytoplasmic membranes of wild-type (SLCC53 and 10403S), ... No evidence was seen for a clear lipid phase transition in any sample. We conclude that the fatty acid anteiso-C(15:0) imparts ... Electron paramagnetic resonance studies of the membrane fluidity of the foodborne pathogenic psychrotroph Listeria ... tau(c) values over the temperature range of -7 degrees C to 50 degrees C were similar for the membranes of strains SLCC53 and ...
Membrane Components, Membrane Fluidity, Membrane Function, Membrane Structure, Peripheral Protein, Plasma Membrane, S. J. ... The mitochondrial inner membrane contains 76 percent protein and only 24 percent lipid. The plasma membrane of human red blood ... Membrane Fluidity The mosaic characteristic of the membrane, described in the fluid mosaic model, helps to illustrate its ... This "elbow room" helps to maintain fluidity in the membrane at temperatures at which membranes with saturated fatty acid tails ...
Characterization of secretory granular membranes from rat parotid gland : Analysis of membrane lipid composition and fluidity. ... Characterization of secretory granular membranes from rat parotid gland: Analysis of membrane lipid composition and fluidity. ... T1 - Characterization of secretory granular membranes from rat parotid gland. T2 - Analysis of membrane lipid composition and ... title = "Characterization of secretory granular membranes from rat parotid gland: Analysis of membrane lipid composition and ...
Elucidating how bamboo salt interacts with supported lipid membranes: influence of alkalinity on membrane fluidity. Authors. ... Elucidating how bamboo salt interacts with supported lipid membranes: influence of alkalinity on membrane fluidity ... Cell membrane; Lipid bilayer; Mobility; Monovalent cation; Fluorescence recovery after photobleaching. Issue Date. 2015-07. ... It was demonstrated that, with increasing ionic strength of the bamboo salt solution, the fluidity of a lipid bilayer increased ...
... determine the lipid bilayer physical properties such as fluidity. Membranes in cells typically define enclosed spaces or ... Proteins are adapted to high membrane fluidity environment of lipid bilayer with the presence of an annular lipid shell, ... Lipid rafts occur when lipid species and proteins aggregate in domains in the membrane. These help organize membrane components ... LipidsEdit. The biological membrane is made up of lipids with hydrophobic tails and hydrophilic heads.[6] The hydrophobic tails ...
In recent years it has become obvious that protein complexes and lipids are not uniformly distributed within membranes. Current ... Flotillin-mediated membrane fluidity controls peptidoglycan synthesis and MreB movement Final publishers version, 2 MB, PDF ... Loss of flotillins leads to a decrease in membrane fluidity that in turn leads to alterations in MreB dynamics and, as a ... Flotillin-mediated membrane fluidity controls peptidoglycan synthesis and MreB movement. Zielińska, A., Savietto, A., de Sousa ...
Lipid analyses and fluidity studies by electron spin resonance of red cell membranes in hereditary high red cell membrane ... Membrane lipid analyses and electron spin resonance (ESR) studies of membrane fluidity were carried out on the red cells of a ... Lipid analyses and fluidity studies by electron spin resonance of red cell membranes in hereditary high red cell membrane ... and cholesterol were found in the membrane lipids of the affected patient, despite normal plasma lipids. The order parameter of ...
  • This study reveals that atheroprone flow induces integrin α5 translocation into lipid rafts and hence activation to cause endothelial dysfunction in vitro and in vivo. (pnas.org)
  • Membrane lipid rafts and integrins are crucial for shear stress-regulated endothelial function. (pnas.org)
  • In this study, we investigate the role of lipid rafts and integrin α5 in regulating the inflammatory response in endothelial cells (ECs) under atheroprone versus atheroprotective flow. (pnas.org)
  • Among 396 proteins redistributed in lipid rafts, integrin α5 was the most significantly elevated in lipid rafts under OS. (pnas.org)
  • Lipid rafts occur when lipid species and proteins aggregate in domains in the membrane. (wikipedia.org)
  • The mechanism of action of elisidepsin (PM02734, Irvalec ® ) is assumed to involve membrane permeabilization via attacking lipid rafts and hydroxylated lipids. (mdpi.com)
  • Number and brightness analysis and fluorescence anisotropy experiments showed that hypoxia decreased the clustering of lipid rafts and altered the structure of the plasma membrane. (mdpi.com)
  • Lipid rafts have been implicated in the regulation and activation of several important receptor complexes in the immune system, including the TLR4 complex. (jimmunol.org)
  • EtOH provides an example of an immunomodulatory drug that acts at least in part by modifying lipid rafts, and it could represent a model to probe the relationships between rafts, receptor complexes, and signaling. (jimmunol.org)
  • Thus, it is interesting that results have recently been reported indicating that GABA A , N -methyl- d -asparate, and 2-amino-5-hydroxy-5-methyl-4-isoxazolepropion acid receptors are associated with lipid rafts ( 12 , 13 , 14 , 15 ). (jimmunol.org)
  • Through preferentially modifying "lipid rafts" within tumor plasma membranes, EPA and DHA have the potential to modulate the physicochemical properties of various receptors and cytokines essential to tumor signal transduction, growth and proliferation. (dsm.com)
  • By combining molecular dynamics simulations with experiments, we uncover a remarkable sensitivity of the transcriptional regulator Mga2 to the abundance, position, and configuration of double bonds in lipid acyl chains, and provide insights into the molecular rules of membrane adaptation. (nature.com)
  • M. Sinensky, K.P. Minneman and P.B. Molinoff, Increased membrane acyl chain ordering activates adenylate cyclase, J. Biol. (springer.com)
  • The low-temperature adaptation mechanisms of membranes involve a reduction in acyl chain length, the introduction of double bonds by desaturase enzymes, or branching of the acyl chains by methyl groups. (asm.org)
  • Bergström, Samuelsson and others in 1964 added to the knowledge of role of lipids in the body by finding that essential fatty acid arachidonate was the biosynthetic precursor of the prostaglandins with their effects on inflammation and other diseases. (news-medical.net)
  • In the present study, we documented the promising role of thyroid hormones status in animals in modulation of Na + -P i transport activity in intestinal brush border membrane vesicles (BBMV) which was accompanied with alterations in BBM lipid composition and fluidity. (springer.com)
  • Reinforcement of the membrane with more complex lipid components is thus thought to be beneficial for the generation of more tolerant organisms. (asm.org)