Fluorescence Probes Unravel Asymmetric Structure of Membranes

Schroeder, Friedhelm

doi:10.1007/978-1-4899-1698-3_2

Cited by 27 publications

(10 citation statements)

References 326 publications

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“…In an analogous study, it was reported that the dansyl group attached to the polar head group in dansylphosphatidylethanolamine experienced decreased polarization in cholesterol-rich model membranes, suggesting in cholesterol-rich microdomains ( 67 ). Furthermore, cholesterol is enriched in the cytofacial leafl et of L-cell plasma membranes, thereby making the intermolecular distance between DChol (enriched in cytofacial leafl et) and Alexa Fluor CT-B (exclusively at the exofacial leaflet) too great for effi cient FRET ( 1,68 ). Conversely, FRET between DChol and DiD was effi cient, because DiD is preferentially distributed into more ordered lipids and the cytofacial leafl et is more ordered ( 2,6,26,44,45,52,69 ).…”

Section: Discussionmentioning

confidence: 99%

Use of dansyl-cholestanol as a probe of cholesterol behavior in membranes of living cells

Huang

McIntosh

Atshaves

et al. 2010

Journal of Lipid Research

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Section: Discussionmentioning

confidence: 99%

Use of dansyl-cholestanol as a probe of cholesterol behavior in membranes of living cells

Huang

McIntosh

Atshaves

et al. 2010

Journal of Lipid Research

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“…Individual leaflet fluidity measurement was based on the procedure of Schroeder (1985), with slight modifications (Nikolova‐Karakashian et al., 1992). The mechanism involves partitioning of the fluorescent probes (donor) into both leaflets of cellular plasma membranes linked to a quenching agent (acceptor) attached to only the outer membrane monolayer.…”

Section: Methodsmentioning

confidence: 99%

Cell culturing in a three‐dimensional matrix affects the localization and properties of plasma membrane cholesterol

Stefanova

Staneva

Petkova

et al. 2009

Cell Biology International

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Most in vitro studies use 2-dimensional (2D) monolayer cultures, where cells are forced to adjust to unnatural substrates that differ significantly from the natural 3-dimensional (3D) extracellular matrix that surrounds cells in living organisms. Our analysis demonstrates significant differences in the cholesterol and sphingomyelin content, structural organization and cholesterol susceptibility to oxidation of plasma membranes isolated from cells cultured in 3D cultures compared with conventional 2D cultures. Differences occurred in the asymmetry of cholesterol molecules and the physico-chemical properties of the 2 separate leaflets of plasma membranes in 2D and 3D cultured fibroblasts. Transmembrane distribution of other membrane phospholipids was not different, implying that the cholesterol asymmetry could not be attributed to alterations in the scramblase transport system. Differences were also established in the chemical activity of cholesterol, assessed by its susceptibility to cholesterol oxidase in conventional and "matrix" cell cultures. The influence of plasma membrane sphingomyelin and phospholipid content on cholesterol susceptibility to oxidation in 2D and 3D cells was investigated with exogenous sphingomyelinase (SMase) and phospholipase C (PLC) treatment. Sphingomyelin was more effective than membrane phospholipids in protecting cholesterol from oxidation. We presume that the higher cholesterol/sphingomyelin molar ratio is the reason for the higher rate of cholesterol oxidation in plasma membranes of 3D cells.

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“…The equation is then solved for esvrot, the percent distribution of sterol in the exofacial leaflet. Cytofacial leaflet sterol equals 100% -C~IeroI.This method is based on the exchange of a molecule of dehydroergosterol for a molecule of cholesterol (Schroeder, 1985;Schroeder et al, l991a;. The total amount of dehydroergosterol was measured in SPMs by using an HPLC Absorbosphere C 18 column (diameter, 5 tam, length, 250 mm; Ailtech Assoc.…”

Section: Cholesterol In Brain Of Knockout Mice 1663mentioning

confidence: 99%

Transbilayer Distribution of Cholesterol Is Modified in Brain Synaptic Plasma Membranes of Knockout Mice Deficient in the Low‐Density Lipoprotein Receptor, Apolipoprotein E, or Both Proteins

Igbavboa

Avdulov

Chochina

et al. 1997

Journal of Neurochemistry

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Abstract:Both apolipoprotein E (apoE) and the low-density lipoprotein (LDL) receptor are present in brain; however, little is known regarding the function of these proteins in brain, in particular with respect to brain cholesterol. The role of apoE and the LDL receptor in modulating the transbilayer or asymmetric distribution of cholesterol in the exofacial and cytofacial leaflets of synaptic plasma membranes (SPM5) was examined in mutant mice deficient in apoE, the LDL receptor, or both proteins by using the fluorescent sterol dehydroergosterol and fluorescent quenching procedures. Fluidity of the exofacial and cytofacial leaflets was also measured. Cholesterol asymmetry of SPMs was altered in the mutant mice, with the largest effect observed in the LDL receptor-deficient mice. There was an approximately twofold increase in the percent distribution of cholesterol in the exofacial leaflet of the LDL receptor-deficient mice (32%) compared with C57BL/6J mice (15%). Mice deficient in apoE or both proteins also showed a significantly higher percent distribution of cholesterol (23 and 26%, respectively) in the exofacial leaflet compared with the C57BL/6J mice. Although the percent distribution of cholesterol was highest in the exofacial leaflet of the LDL receptor-deficient mice, fluidity of the exofacial leaflet of that group was significantly lower. However, the cholesterol-to-phospholipid ratio of SPMs of the LDL receptor-deficient mice was significantly lower, and this difference was largely the result of a significant increase in the total amount of SPM phospholipid. This study demonstrates for the first time that SPM lipid structure is altered in mice deficient in apoE or the LDL receptor. Although the mechanism that maintains the asymmetric distribution of cholesterol in plasma membranes is not well understood, data of the present experiments indicate that both apoE and the LDL receptor are involved in maintaining the transbilayer distribution of cholesterol. Key Words: Apolipoprotein ELow-density lipoprotein receptor-CholesterolBrain-Fluidity.

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Fluorescence Probes Unravel Asymmetric Structure of Membranes

Cited by 27 publications

References 326 publications

Use of dansyl-cholestanol as a probe of cholesterol behavior in membranes of living cells

Use of dansyl-cholestanol as a probe of cholesterol behavior in membranes of living cells

Cell culturing in a three‐dimensional matrix affects the localization and properties of plasma membrane cholesterol

Transbilayer Distribution of Cholesterol Is Modified in Brain Synaptic Plasma Membranes of Knockout Mice Deficient in the Low‐Density Lipoprotein Receptor, Apolipoprotein E, or Both Proteins

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