Dependence of lipid membrane phase transition temperature. A liquid crystal lc is thermotropic if the order of its components clarify is determined or changed by temperature if temperature is too high, the rise in energy and therefore in motion of the components will induce a phase transition. Aug 18, 2005 the role of lipid domain size and protein lipid interfaces in the thermotropic phase transition of dipalmitoyl phosphatidylcholine dppc and dimyristoyl phosphatidylcholine dmpc bilayers in nanodiscs was studied using smallangle xray scattering saxs, differential scanning calorimetry dsc, and generalized polarization gp of the. An approximate cooperativity analysis by dsc of phase. Liposomes have been widely used as model membranes and in drug delivery, as their basic properties can easily be varied to target desired properties lipid composition, concentration, water content, media different buffers, varying ionic strength, ph, etc. This paper presents a method which combines the statistical analysis with texture structural analysis called local binary gray level cooccurrence matrix lbglcm to investigate the phase transition temperatures of thermotropic alkyloxy benzoic acid oba, and 12 liquid crystals. In both phases the lipid molecules are constrained to the two dimensional plane of the membrane, but in liquid phase bilayers the molecules diffuse freely within this plane. Structure of a steroidlecithin system below and above the. Physicochemical properties of liposomes depend on many factors such as ionic strength, ph and temperature. At 310 k, the area per dppc without resveratrol is 51. Membrane lipid phase transitions and phase organization. Nanoscale thermotropic phase transitions enhance photothermal.
The sugar anomeric effect on the thermotropic phase transition of stearyl glucoside was investigated. Transition temperatures of thermotropic liquid crystals from. Lipidomics is crucial to understanding cellular physiology and pathology, and lipid profiling for disease phenotype analysis is a rapidly growing area in translational medical research. Standard analysis to study the phase transition through differential scanning calorimetry dsc, and optical polarizing microscopy opm was applied. We focus on isoelectric cationic lipiddna condensates where the number of cationic lipids equals the number of phosphate groups on the dna. A database of lipid phase transition temperatures, enthalpy changes, and associated information chapter pdf available january 1996 with 532 reads how we measure reads. Differential scanning calorimetry of bilayer membrane. Project description computer science and engineering. The phase transitions of binary lipid mixtures are studied by a combination of peltierelementbased adiabatic scanning calorimetry pasc and quartz crystal microbalance with dissipation monitoring qcmd. Phase transitions in lipid membranes april 2009 author. The next four sections deal with the major thrusts of the proposed study. A new lipid software workflow for processing orbitrapbased. All the above mentioned characteristics for the phases l 0, l and p 0, plus others described qualitatively below, are shown in the phase diagram of g. A general discussion on models is made and some concrete examples are presented in more detail.
A new lipid software workflow for processing orbitrapbased global lipidomics data in translational and systems biology research david a peake, 1 yasuto yokoi,2 junhua wang, and yingying huang1 1thermo fisher scientific, san jose, usa. For any imaging techniques in which the question is a transition from closetophaseseparated to actually phaseseparated, we expect sensitivity to lightinduced macroscopic domains. The cell membranes of almost all organisms and many viruses are made of a lipid bilayer, as are the nuclear membrane surrounding the cell nucleus, and. The dsc heating curves of lipid bilayers show two phase transitions.
Hydration pressure and phase transitions of phospholipids ii. Such a twostep change was also seen in the gp value and is expected to result from the change in the vertical location of prodan molecules with the thermotropic phase transition of liposome membrane. Phase transitions in lipid membranes ibrahim cisse department of physics, university of illinois urbanachampaign contact. As of this writing, the database is current through june, 1990 and is approaching 10 000 records in length.
All lipids have a characteristic temperature at which they undergo a transition from the gel to liquid phase. If, on the contrary, temperature is too low to support a thermotropic phase, the lc will change to glass phase. Parameters measured for mlvs and luvs of dmpc in hepes buffer. Phase transitions and phase behavior of lipids springerlink.
Lipid thermotropic phase transition database lipidat nist standard reference database 34 avanti polar lipids, inc. Phase transitions and fluidity characteristics of lipids and. This process is experimental and the keywords may be updated as the learning algorithm improves. In this paper we report the contents and present an analysis of lipidat as it refers to fully hydrated 1,2dimyristoylsnglycero3phosphocholine dmpc. The study of the interaction of biosurfactants with membranes is important in order to understand the molecular mechanism of their biological actions. Thermotropic phase behavior and headgroup interactions of.
The nonpolar parts of the propanediols slightly reduce the. For comparison the melting curves of dry liposomes containing pure epc or dmpc are also included in figure 1a. The nonpolar parts of the propanediols slightly reduce the main phase. It was concluded that calorimetric investigations of the thermotropic phase transition of the lipid might only give qualitative using a thermodynamic approach, we will here. Thermotropic phase behavior of hydrogenated soybean. The manifest differences in the properties of the phases must then appear as discontinuities in some derivatives of g. These membranes are flat sheets that form a continuous barrier around all cells. A twocomponent solution theory is studied which incorporates hydrophobic matching as a major contribution to the lipidprotein interactions in biological membranes. These vesicles have membranes which undergo phase transitions. Copperfree click chemistry is a fairly new chemistry that has been commercialized during the past few years. Lipid thermotropic phase transition database lipidat. More and more click chemistry based reagents are becoming available commercially which makes the formulation development much easier for scientists. Phase transitions of lipids and liposomes mettler toledo. Thermotropic phase transition in soluble nanoscale lipid.
We focus on isoelectric cationic lipid dna condensates where the number of cationic lipids equals the number of phosphate groups on the dna. Effects of lipid packing and intermolecular hydrogen bond. Usually liposomes have low permeability to the encapsulated molecules unless the molecule is membrane permeable. In other words, in firstorder transitions there is an abrupt change in the properties of the system at the phase transition temperature. A detailed inspection of the formula showed that there is a qualitative agreement but no quantitative agreement with experimental results 4. Molecular mechanism of resveratrols lipid membrane.
Thermotropic phase behavior and headgroup interactions of the. The systematic study of the mesomorphic phase properties of synthetic and biologically derived lipids began some 30 years ago. This phase boundary line meets the l l boundary line at the lifshitz point 2. Studies of the crystallineliquid crystalline phase transition of lipid model membranes. Apr 14, 2003 the investigation of the solvation process of phospholipids includes the investigation of the thermotropic and piezotropic phase behaviour in presence of nonaqueous polar solvents. Structure of a steroidlecithin system below and above the lipid phase transition. Identification algorithms for product ion, precursor ion, and neutral loss scans. During the phase transition, the equilibrium in distribution of solute between the lipid phases is maintained. Their influence ranges from domain formation in intact biomembranes to membrane protein reconstitution and crystallization. Analysis of the thermograms was performed using the netzsch software package. A data processing tool for the molecular characterization and quantification of lipid species from electrospray mass spectrometry data. The lipid bilayer or phospholipid bilayer is a thin polar membrane made of two layers of lipid molecules. A phase of a thermodynamic system and the states of matter have uniform physical properties.
The phase transition temperature is defined as the temperature required to induce a change in the lipid physical state from the ordered gel phase, where the hydrocarbon chains are fully extended and closely packed, to the disordered liquid crystalline phase, where the hydrocarbon chains are randomly oriented and fluid. Photothermal microscopy, nanoparticles, thermotropic phase transition, liquid crystals, single molecule detection. However, comparable correlations cannot be confidently established if the lamellarnonlamellar phase transition is very broad, is coupled to the melting of the lipid hydrocarbon chains e. Lipid thermotropic phase transition database nist standard reference database 34. This response is known as the phase behavior of the bilayer. H ii phase transitions, andor the reorganization of crystalline polymorphic forms of the lipid occurs e. Users guide nist standard reference database on free shipping on qualified orders. Considering only the lipids a mixture chosen by evolution in part to spontaneously form the bilayer phases that are the fundamental cell membrane structure, a first step for study of heterogeneity is to find the lipid composition of cell membranes van meer et al. Using dsc to characterize thermotropic phase transitions in. Phase transition temperatures for glycerophospholipids phosphatidylcholine phosphatidylglycerol sodium salt product tm c product tm c 12.
The process by which the database was constructed can be viewed as a fourstage sluice down and within. Lipid thermotropic phase transition data base lipidat nist standard reference data. Most lipids exhibit liquid crystallinity and their thermotropic, lyotropic, ionotropic and barotropic behavior has been the subject of intensive study this past three. Lipidat consists of a tabulation of all known mesomorphic and polymorphic phase transition temperatures and enthalpy changes for synthetic and biologicallyderived lipids in the dry and in the partially and fully hydrated states. Studies of crystallineliquid crystalline phase transition of lipid model membranes 3 structure of a steroidlecithin system below and above lipid phase transition. Phase transition temperature soya lecithin intrinsic membrane protein lipid phase transition lateral phase separation these keywords were added by machine and not by the authors. The transition is from the ripple phase p at low tto the smectic a phase l at high t. The theory has an advantage over conventional landau. The term phase transition or phase change is most commonly used to describe transitions between solid, liquid, and gaseous states of matter, as well as plasma in rare cases.
Multiple thermotropic phase transitions in escherichia coli. Thermotropic phase transitions of pure lipids in model membranes and their modifications by membrane proteins, dr. The phase transition temperature is defined as the temperature required to induce a change in the lipid physical state from the ordered gel phase, where the hydrocarbon chains are fully extended and closely packed, to the disordered liquid crystalline phase, where. Transition temperatures of thermotropic liquid crystals. Lipidat, lipidag, the lipid molecular structures database, and database updating. In this work we describe the results of an experimental study of thermotropic phase transition of lipid nanodiscs containing from 140 to 340 lipid molecules. A special geometrical constraint has been discovered which has important implications for the quantitative interpretation of physical effects to lipidprotein interactions. The investigation of the solvation process of phospholipids includes the investigation of the thermotropic and piezotropic phase behaviour in presence of nonaqueous polar solvents.
Interactions of a bacterial biosurfactant trehalose lipid. The photothermal heterodyne imaging technique enabled studies of individual weakly. Hence, the systematic study of the pressure effect. The purpose of this paper is 1 to alert the appropriate scientific communities to the existence of the lipidat resource, 2 to present to these communities the database subset which brings together a wealth of thermodynamic data and associated information on dmpc in a single location, 3 to present an analysis of the data contained in the.
To exploit phase behavior in the spirit of rational design, it is imperative that the rules relating lipid molecular structure and liquid crystal or mesophase behavior be established. A database of lipid phase transition temperatures and enthalpy changes. The solid phase is commonly referred to as a gel phase. Lcms is a powerful technique for the identification and quantitation of cellular lipids. In this respect, a firstorder phase transition is completely correlated, that is completely cooperative. Introduction the major components of biomembrane are protein and lipid, and phospholipid is typical lipid making up biomembrane.
The ideal experimental technique for the determination of thermotropic phase transitions in lyotropic lipid phases for membranes composed of pure. Lcms chromatograms of lipids from wt and ko yeast cerd18. Phase transitions and fluidity characteristics of lipids. This artifact can be minimized by use of low dye concentration, multiphoton excitation, and sensitive cameras moralespenningston et al. Phases and phase transitions of the phosphatidylcholines. Lipidview software enables lipid profiling by searching parent and fragmention masses against a lipid fragment database containing over 25,000 entries and reports a numerical and graphical output for various lipid molecular species, lipid classes, fatty. Dipalmitoyl lecithin hereafter abbreviated as dpl is a typical phospholipid, which is a synthetic lecithin with a fatty acid chain with 16 carbon molecules. Using dsc to characterize thermotropic phase transitions in lipid bilayer membranes. What is the effect of the phase transition temperature of. What is the effect of the phase transition temperature of the. The thermo scientific lipidsearch software processes lcms data. Computational simplicity of the present methodology. The phase transition temperatures gel to liquidcrystalline t m or bilayer to nonbilayer t hex were determined as the temperature at the peak maximum of the second heating scan. The thermotropic phase behavior of zwitterioniccationic binary lipid mixtures is investigated and compared to its corresponding lipidic phase diagram of mixtures complexed with dna.
Differential scanning calorimetry of bilayer membrane phase. The role of lipid domain size and proteinlipid interfaces in the thermotropic phase transition of dipalmitoyl phosphatidylcholine dppc and dimyristoyl phosphatidylcholine dmpc bilayers in nanodiscs was studied using smallangle xray scattering saxs, differential scanning calorimetry dsc, and generalized polarization gp of the lipophilic probe laurdan. A sharp transition 3234 c is also observed for the lipid spinlabeled near the terminal methyl of stearate label at c16, but the. The seminar treats phase transitions in lipid membranes, with the focus on the main lipid bilayer phase transition. Mar, 2011 physicochemical properties of liposomes depend on many factors such as ionic strength, ph and temperature. Multiple thermotropic phase transitions in escherichia coli membranes and membrane lipids a comparison of results obtained by nitroxyl stearate paramagnetic resonance, pyrene excimer fluorescence, and enzyme activity measurements received for publication, march 17, 1975. Figure 1 shows the melting curves of dry epe and mgdg and of the respective 1. Multiple thermotropic phase transitions in escherichia.
There are many reports on thermotropic phase transitions of pe bilayer membranes though, barotropic phasetransition data are quite lacking and only a few data concerning the pressure effect on the bilayer phase transition of certain pes have been reported by some groups including us. During a phase transition of a given medium, certain properties of the medium. Lipids are biological polymers with both a hydrophilic and a hydrophobic part. Compatibility with thermo scientific triple quadrupole, ion trap, and orbitrap lcms systems. Broadly, at a given temperature a lipid bilayer can exist in either a liquid or a solid phase. A new lipid software workflow for processing orbitrap. The phase properties of lipids have farreaching consequences in membrane biology. Lipid complexity from the lipid maps structure database lmsd 2 fa figure 1.
Phase transition temperatures for glycerophospholipids. Hydration pressure and phase transitions of phospholipids. The first section summarizes the results from prior nsf support. Thermotropic phase behavior of cationic lipid dna complexes. A complete analysis would involve assaying the lipids of the given cell membrane, both. Calorimetric and spectroscopic studies of the thermotropic.
Textures of the homeotropically aligned liquid crystal compounds are recorded as a function of. When in solution, lipids can regroup to form vesicles. The thermotropic phase behavior of lipid bilayer model membranes composed of the evennumbered, nsaturated 1,2diacyl phosphatidylserines was studied by differential scanning calorimetry and by fouriertransform infrared and 31pnuclear magnetic resonance spectroscopy. It is concluded that the present method is successful in identifying the phase transition temperatures of thermotropic liquid crystals alkyloxy benzoic acids of even series using statistical analysis with texture structural analysis called local binary gray level cooccurrence matrix lbglcm.
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