Phospholipid phase transitions in model and biological membranes as studied by infrared spectroscopy

Mantsch, Henry H.; McElhaney, Ronald N.

doi:10.1016/0009-3084(91)90077-o

Cited by 525 publications

(486 citation statements)

References 20 publications

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“…It was also demonstrated that CLL cells have a lower lipid content than normal peripheral mononuclear cells, and this is due to a reduction in methylene and ester groups (in fatty acids, see [7]). This situation contrasts with other tumors, which are usually found to have a higher lipid content than normal cells (for tissues and cell lines see [13,16,25,261).…”

Section: Discussionmentioning

confidence: 99%

“…The spectral features marked 1, 2 and 3 are well-known methyl and methylene bands, highly characteristic for lipids in the membranes and other lipid structures. Band 1, located at 1468 cm-', originates from the CHa bending vibration of lipid acyl chains, while band 2, centered around 1455 cm-', arises from the asymmetric CHs deformation vibration of methyl groups [7]. Band 3, centered around 1440 cm-', is a specific methylene group vibration in fatty acids and amino acids.…”

Section: Cluster Analysismentioning

confidence: 99%

“…This feature may be partly due to an intrinsic defect in the leukemic cells, as cytogenetic abnormalities are present in 56-65% of cases [l, 21. Typically, this is a disease of accumulation rather than proliferation, and bcl-2 is overexpressed in most patients, possibly as a result of DNA hypomethylation, causing a reduction in spontaneous apoptosis [3,4]. However, the leukemic cell populations are not homogeneous and there is variation in the cells of an individual in morphology [l], buoyant density [5], immunoglobulin content [6] and chromosomal content PI* Fourier transform infrared (FI'-IR) spectroscopy has become a powerful tool for the analysis of cell components, such as membranes [7], proteins [8] and Abbreviations: FT-IR, Fourier transform infrared spectroscopy; CLL, chronic lymphocytic leukemia. nucleic acids [9], as well as for complex biological materials, such as tissues , body fluids [14,15] or cell cultures [16].…”

Section: Introductionmentioning

confidence: 99%

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Study of chronic lymphocytic leukemia cells by FT-IR spectroscopy and cluster analysis

et al. 1996

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Section: Discussionmentioning

confidence: 99%

Section: Cluster Analysismentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

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Study of chronic lymphocytic leukemia cells by FT-IR spectroscopy and cluster analysis

et al. 1996

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“…These are the symmetric CH 3 deformation at 1385 cm À1 of either CPEO3 or POPC, 36 and the prominent band at 1514 cm À1 that is assigned to the weakly hydrogen-bonded N-H group (see ESI †). The changes in this difference spectrum can be interpreted in terms of a reorientation of the CPEO3 molecules.…”

Section: Electric Field Effects On the Tblmmentioning

confidence: 99%

Voltage-dependent structural changes of the membrane-bound anion channel hVDAC1 probed by SEIRA and electrochemical impedance spectroscopy

Kozuch

Weichbrodt

Millo

et al. 2014

Phys. Chem. Chem. Phys.

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The voltage-dependent anion channel (VDAC) is a transmembrane protein that regulates the transfer of metabolites between the cytosol and the mitochondrium. Opening and partial closing of the channel is known to be driven by the transmembrane potential via a mechanism that is not fully understood. In this work, we employed a spectroelectrochemical approach to probe the voltage-induced molecular structure changes of human VDAC1 (hVDAC1) embedded in a tethered bilayer lipid membrane on a nanostructured Au electrode. The model membrane consisted of a mixed self-assembled monolayer of 6-mercaptohexanol and (cholesterylpolyethylenoxy)thiol, followed by the deposition of 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine vesicles including hVDAC1. The stepwise assembly of the model membrane and the incorporation of hVDAC1 were monitored by surface enhanced infrared absorption and electrochemical impedance spectroscopy. Difference spectra allowed for identifying the spectral changes which may be associated with the transition from the open to the ''closed'' states by shifting the potential above or below the transmembrane potential determined to be ca. 0.0 V vs. the open circuit potential. These spectral changes were interpreted on the basis of the orientation-and distancedependent IR enhancement and indicate alterations of the inclination angle of the b-strands as crucial molecular events, reflecting an expansion or contraction of the b-barrel pore. These protein structural changes that do not confirm nor exclude the reorientation of the a-helix are either directly induced by the electric field or a consequence of a potential-dependent repulsion or attraction of the bilayer.

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“…The wavenumbers of the symmetric (ν s CH 2 ) and antisymmetric (ν as CH 2 ) methylene stretching vibrational bands provide information about the conformational order of the alkyl chain. 38,39 The temperature dependency of the wavenumbers of both methylene stretching vibrational bands of PC-C17pPhC17-PC and PC-C17pPhC17-OH is depicted in Figure 3, and in the SI in Figures S5, S6. 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 structures.…”

Section: Dsc and Ftirmentioning

confidence: 99%

The Headgroup (A)Symmetry Strongly Determines the Aggregation Behavior of Single-Chain Phenylene-Modified Bolalipids and Their Miscibility with Classical Phospholipids

et al. 2014

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In the present work, we describe the synthesis of two single-chain phenylene-modified bolalipids, namely PC-C17pPhC17-PC and PC-C17pPhC17-OH, with either symmetrical (phosphocholine) or asymmetrical (phosphocholine and hydroxyl) headgroups using a Sonogashira cross coupling reaction as key-step. The temperature-dependent aggregation behavior of both bolalipids in aqueous suspension was studied using transmission electron microscopy (TEM), differential scanning calorimetry (DSC), Fourier-transform infrared (FTIR) spectroscopy, small angle neutron scattering (SANS), and X-ray scattering. We show that different headgroup symmetries lead to a change in the aggregation behavior: Whereas PC-C17pPhC17-PC forms nanofibers with a diameter of 5.7 nm that transform into small ellipsoidal micelles at 23 °C, the PC-C17pPhC17-OH self-assembles into lamellae with bolalipid molecules in an antiparallel orientation up to high temperatures. Furthermore, the mixing behavior of both bolalipids with bilayer forming phospholipids (DPPC and DSPC) was studied by means of DSC and TEM. The aim was to stabilize bilayer membranes formed of phospholipids in order to improve these mixed lipid vesicles for drug delivery purposes. We show that the symmetrical PC-C17pPhC17-PC is miscible with DPPC and DSPC, however, closed lipid vesicles are not observed and elongated micelles and bilayer fragments are found instead. In contrast, the asymmetrical PC-C17pPhC17-OH shows no miscibility with phospholipids at all.

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Phospholipid phase transitions in model and biological membranes as studied by infrared spectroscopy

Cited by 525 publications

References 20 publications

Study of chronic lymphocytic leukemia cells by FT-IR spectroscopy and cluster analysis

Study of chronic lymphocytic leukemia cells by FT-IR spectroscopy and cluster analysis

Voltage-dependent structural changes of the membrane-bound anion channel hVDAC1 probed by SEIRA and electrochemical impedance spectroscopy

The Headgroup (A)Symmetry Strongly Determines the Aggregation Behavior of Single-Chain Phenylene-Modified Bolalipids and Their Miscibility with Classical Phospholipids

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