Abstract:
:The properties of cholesterol in bilayers of egg phosphatidylcholine (PC) were investigated directly by means of 2H-NMR of specifically-deuterated species (C3, C7, C26, C27). Quadrupole splittings were a measure of molecular ordering, and relaxation times T1 and T2e were indicators of rates of motion. The importance of the use of echoes for spectral acquisition is emphasised, particularly to obtain accurate values of the quadrupole splitting. In the case of overlapping powder patterns from two labelled positions, the use of the absolute value mode of spectral presentation is shown to yield reasonable estimates of the individual quadrupole splittings. Spectral properties were monitored as a function of cholesterol concentration and temperature. Increasing cholesterol concentration led to a high degree of ordering for the rigid ring system of cholesterol, approaching a molecular order parameter of 0.8 at 50 mol% cholesterol. The isopropyl methyl groups were in all cases less ordered and more mobile than the ring system, but responded in a similar fashion to variable cholesterol concentration and temperature. The observation of a minimum in the temperature dependence of T1 for cholesterol-7,7-d2 led to a direct estimate of its correlation time for molecular motion, 3.5 X 10(-9) S rad-1. This indicates that the overall rate of motion of cholesterol is considerably slower than that of the lipids in which it is located. The short T2e values suggest that the motional spectrum of cholesterol is rich in low frequencies. The parallel temperature and cholesterol dependences of quadrupole splittings for different positions on the rigid ring system of cholesterol indicate that the position of the axis of motional averaging of the molecule is not changing, and is the same as that determined in an earlier study. It is emphasised that the steep temperature dependence and small quadrupole splittings for the chain isopropyl methyl groups of cholesterol do not necessarily indicate a high degree of disorder, but may be due to their axes of motional averaging lying at angles close to 54 degrees with respect to the director of the ordered lipids.
journal_name
Chem Phys Lipidsjournal_title
Chemistry and physics of lipidsauthors
Taylor MG,Akiyama T,Saitô H,Smith ICdoi
10.1016/0009-3084(82)90072-xsubject
Has Abstractpub_date
1982-12-01 00:00:00pages
359-79issue
4eissn
0009-3084issn
1873-2941pii
0009-3084(82)90072-Xjournal_volume
31pub_type
杂志文章abstract::High density lipoprotein (HDL) is prone to modification by the oxidizing and chlorinating agent hypochlorite anion (OCl-). Oxidation of apolipoprotein (apo) A-I, the major protein in HDL, reduces ABCA-1 mediated cholesterol efflux and other protective responses to HDL. The apoA-I mimetic peptide 4F has been shown to u...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/j.chemphyslip.2019.01.009
更新日期:2019-03-01 00:00:00
abstract::In the last 30 years, ceramides have been found to mediate a myriad of biological processes. Ceramides have been recognized as bioactive molecules and their metabolizing enzymes are attractive targets in cancer therapy and other diseases. The molecular mechanism of action of cellular ceramides are still not fully esta...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章,评审
doi:10.1016/j.chemphyslip.2018.09.013
更新日期:2018-11-01 00:00:00
abstract::2-N-(Hexadecanoyl)-amino-4-nitrophenyl phosphorylcholine-hydroxide a compound resembling sphingomyelin is synthesized. It is cleaved by sphingomyelinase to the chromogenic N-acylaminonitrophenyl moiety. Phospholipase C preparations do not hydrolyze this compound. The starting material is 2-amino-4-nitrophenol which wh...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/0009-3084(76)90015-3
更新日期:1976-02-01 00:00:00
abstract::The stratum corneum (SC), the outermost layer of the mammalian skin, is the main skin barrier. Ceramides (CERs) as the major constituent of the SC lipid matrix are of particular interest. At the moment, 11 classes of CERs are identified, but the effect of each single ceramide species is still not known. Therefore in t...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/j.chemphyslip.2009.10.007
更新日期:2010-01-01 00:00:00
abstract::In the first part of this article, chemical and physical stability of aqueous liposome dispersions have been addressed. Chemical stability of phospholipids has been considered in two parts: oxidation and hydrolysis. Major attention has been paid to hydrolysis kinetics of phospholipids as a function of pH, temperature,...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章,评审
doi:10.1016/0009-3084(93)90053-6
更新日期:1993-09-01 00:00:00
abstract::Bile acids directly related to liver and intestinal function are used as indicators of hepatobiliary and intestinal diseases. Here, we have designed and realized a capillary sensory platform for the detection of bile acids using liquid crystals (LCs). LC droplets confined in micro-capillaries are homeotropically align...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/j.chemphyslip.2017.02.003
更新日期:2017-04-01 00:00:00
abstract::2-Hydroxypropane-1,3-bis(arsonic acid) after six successive reactions gives the arsinolipid 2-acyloxy-As, As'-bis[2,3-di(acyloxy)propyl]propane-1,3-diylbis(arsinic acid) in 20-40% overall yields. This arsinolipid is a non-isosteric analogue of the fully acylated cardiolipin. The R- and S-glycidol, used to create the b...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/s0009-3084(02)00009-9
更新日期:2002-08-01 00:00:00
abstract::Chain-ordering/melting transition in a series of saturated diacylphosphatidylcholines (PCs) in aqueous dispersions have been studied experimentally (calorimetric and ultrasonic techniques) and theoretically (an Ising-like lattice model). The shape of the calorimetric curves was compared with the theoretical data and i...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/j.chemphyslip.2007.08.004
更新日期:2007-12-01 00:00:00
abstract::We examine the effects of cholesterol (Chol) on the mechanical properties of membranes consisting of 16:0/18:1 POPC lipid and of lipids with conjugated linoleic acid (CLA), cis-9/trans-11 CLA (C9T11) and trans-10/cis-12 CLA (T10C12). Atomistic molecular dynamics (MD) simulations of POPC-Chol and CLA-Chol mixtures at v...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/j.chemphyslip.2013.12.012
更新日期:2014-02-01 00:00:00
abstract::Reported herein is the synthesis of (+)- and (-)-(1,3/2)-1-O-(phosphocholine)-2,3-O-dihexanoylcyclopentane-1,2, 3-triol. These are the enantiomers of a contrained analogue of dihexanoylphosphatidylcholine in which the glycerol backbone is replaced by all-trans cyclopentane-1,2,3-triol. Evidence is presented to demonst...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/0009-3084(88)90017-5
更新日期:1988-03-01 00:00:00
abstract::Ceriporiopsis subvermispora is a selective white-rot fungus that secretes alk(en)ylitaconic acids named ceriporic acids, known as ion redox silencers. In this study, we analysed a series of extracellular lipid-related metabolites produced by the fungus and found that a wide variety of ceriporic acids and fatty acids, ...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/j.chemphyslip.2011.10.007
更新日期:2012-01-01 00:00:00
abstract::3 beta-Hydroxy-5 alpha-cholestan-15-one (2a) and its 14 beta-epimer 2b were prepared from 3 beta-acetoxy-5 alpha-cholest-8(14)-ene (3). Hydroboration of 3 at 45-50 degrees C gave a mixture of 5 alpha,14 alpha-cholestane-3 beta,15 alpha-diol and 5 alpha,14 beta-cholestane-3 beta,15 beta-diol, which were separated on si...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/0009-3084(94)90106-6
更新日期:1994-10-20 00:00:00
abstract::Previously unknown 4,5-epoxy-N-acetyl-sphingosine (1) was synthesized by epoxidation of N-acetyl-sphingosine with 1,1-dimethyldioxirane. A by-product generated by HPLC purification is the tetrahydrofuryl derivative of acetamide (2). Mainly allylic oxidation was observed when natural ceramides were reacted with dimethy...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/s0009-3084(00)00208-5
更新日期:2001-02-01 00:00:00
abstract::The ionic transport properties, capacitance and breakdown voltage of bilayer macrovesicles made from lecithin, dodecaprenol and their mixtures have been studied. The electrical measurements showed that polyprenol in lipid bilayers increases membrane permeability and elasticity, and decreases membrane thickness. Some p...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/0009-3084(86)90116-7
更新日期:1986-03-01 00:00:00
abstract::The transformation between a gel and a fluid phase in dipalmitoyl-phosphatidylcholine (DPPC) bilayers has been simulated using a coarse grained (CG) model by cooling bilayer patches composed of up to 8000 lipids. The critical step in the transformation process is the nucleation of a gel cluster consisting of 20-80 lip...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/j.chemphyslip.2005.03.001
更新日期:2005-06-01 00:00:00
abstract::The melting behavior of members of newly synthesized series of rac-1,2-diglycerides with substituted phenyl groups or a benzyl group on the 3-position was investigated with differential scanning calorimetry (DSC). Solution crystallized samples had single melting temperatures, higher than those of the quenched or annea...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/0009-3084(78)90030-0
更新日期:1978-10-01 00:00:00
abstract::A fluorescence spectroscopy global data analysis environment is described. Within this analysis environment, multidimensional fluorescence decay data (time and frequency domains) can be analyzed in terms of a wide variety of photophysical models. A generalized compartmental analysis structure is utilized, where one ca...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/0009-3084(89)90052-2
更新日期:1989-06-01 00:00:00
abstract::Mycobacteria are intracellular pathogens that can invade and survive within host macrophages. Mycobacterial infections remain a major cause of mortality and morbidity worldwide, with serious concerns of emergence of multi and extensively drug-resistant tuberculosis. While significant advances have been made in identif...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/j.chemphyslip.2018.03.004
更新日期:2018-07-01 00:00:00
abstract::Low density lipoprotein (LDL) cholesterol is known to be oxidized both in vitro and in vivo giving rise to oxygenated sterols. Conflicting results, however, have been reported concerning both the nature and the relative concentrations of these compounds in oxidized human LDL. We examined the extracts obtained from Cu(...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/0009-3084(92)90057-v
更新日期:1992-10-01 00:00:00
abstract::A fluorescent assay for Clostridium perfringens phospholipase C is described using 1-palmitoyl-2-[6(pyren-1-yl)hexanoyl]-sn-glycero-3- phospho-N-(trinitrophenyl)aminoethanol (PPHTE) as the substrate. This method is based on the decrease of the quenching of pyrene monomer fluorescence when phospholipase C hydrolyzes PP...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/0009-3084(91)90064-i
更新日期:1991-08-01 00:00:00
abstract::When we subjected 11-dehydrothromboxane B2 (11-DTXB2), a metabolite of arachidonic acid, to standard chemical derivatization procedures we obtained a mixture of several products. Separation of the components was carried out by gas chromatography and their identification was accomplished through the study of their mass...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/0009-3084(95)02452-o
更新日期:1995-08-01 00:00:00
abstract::Seven members of the methyl-6-O-(n-acyl)-α-D-glucopyranosides have been synthesised and their transitional properties determined. The undecanoyl and octadecanoyl members do not exhibit liquid crystallinity while the members having chain lengths between dodecanoyl and hexadecanoyl exhibit a monotropic smectic A phase. ...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/j.chemphyslip.2010.11.007
更新日期:2011-02-01 00:00:00
abstract:BACKGROUND:In this study, we aimed to compare the serum lipid profile and fatty acid (FA) compositions of erythrocyte membrane (EM) and plasma in three different patient groups (group 1: type 2 diabetes mellitus (T2DM)+end-stage renal disease (ESRD), group 2: ESRD, group 4: T2DM) and healthy controls (group 3) simultan...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/j.chemphyslip.2013.12.011
更新日期:2014-02-01 00:00:00
abstract::Interaction of a cationic phenazinium dye, phenosafranin (PSF), with the anionic liposomal vesicle/bilayer of dimyristoyl-L-alpha-phosphatidylglycerol (DMPG) has been demonstrated using steady state and time resolved fluorescence and fluorescence anisotropy techniques. The charge transfer emission spectrum of PSF show...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/j.chemphyslip.2009.10.003
更新日期:2010-01-01 00:00:00
abstract::In X-ray diffraction studies of hydrated (greater than 60%) cholesterol/dioleoylphosphatidylcholine mixtures the lipid packing band showed an abrupt transition from liquid crystal-type to gel-type position and definition at a temperature which decreased progressively to almost -50 degrees C as the proportion of choles...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/0009-3084(88)90115-6
更新日期:1988-01-01 00:00:00
abstract::A prevalent model for the function of rhodopsin centers on the metarhodopsin I (MI) to metarhodopsin II (MII) conformational transition as the triggering event for the visual process. Flash photolysis techniques enable one to determine the [MII]/[MI] ratio for rhodopsin in various recombinant membranes, and thus inves...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章,评审
doi:10.1016/0009-3084(94)90180-5
更新日期:1994-09-06 00:00:00
abstract::Bacteriophage M13 major coat protein is extensively used as a biophysical, biochemical, and molecular biology reference system for studying membrane proteins. The protein has several elements that control its position and orientation in a lipid bilayer. The N-terminus is dominated by the presence of negatively charged...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章,评审
doi:10.1016/j.chemphyslip.2006.02.023
更新日期:2006-06-01 00:00:00
abstract::Perturbations induced by ethylazinphos on the physical organization of dipalmitoylphosphatidylcholine (DPPC) and DPPC/cholesterol membranes were studied by differential scanning calorimetry (DSC) and fluorescence polarization of 2-, 6-, 12-(9-anthroyloxy) stearic acids and 16-(9-anthroyloxy) palmitic acid. Ethylazinph...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/s0009-3084(98)00105-4
更新日期:1999-02-01 00:00:00
abstract:PURPOSE:The present research work involves Quality by Design (QbD)-based fabrication of lipid nanoconstructs (LNC) of paliperidone (PPD) bearing superior biopharmaceutical attributes. METHODS:LNC of paliperidone was prepared by melt emulsification-probe sonication and high-pressure homogenization method followed by op...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/j.chemphyslip.2020.105005
更新日期:2021-01-01 00:00:00
abstract::To exploit the potential of Didodecyldimethylammonium bromide (D12DAB) as a core lipidic constituent, an attempt was made to fabricate and optimize cationic nanostructured lipid carriers (cNLCs) using a cost-effective microemulsification methodology. Designed composition was optimized by studying the effect of differe...
journal_title:Chemistry and physics of lipids
pub_type: 杂志文章
doi:10.1016/j.chemphyslip.2016.02.006
更新日期:2016-03-01 00:00:00