Cholesterol-free phospholipid domains may be the membrane feature selected by Nε-dansyl-L-lysine and merocyanine 540

Humphries, Gillian M. K.; Lovejoy, John P.

doi:10.1016/0006-291x(83)90370-4

Cited by 44 publications

(16 citation statements)

References 10 publications

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“…Differential scanning-calorimetry studies suggest the formation of gramicidin A clusters in dipalmitoylglycerophosphocholine bilayers when a peptide mole fraction of 0.05 is exceeded [18]. MC540 has been suggested to be preferentially incorporated into phospholipid-rich membrane regions [27]. The hypothesis that MC540 is excluded from gramicidin-A clusters is confirmed by the observation that A, , , remains almost unchanged in the presence of the polypeptide.…”

Section: Factors Leading To Mc540 Dimerization In Membranessupporting

confidence: 63%

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The components of merocyanine‐540 absorption spectra in aqueous, micellar and bilayer environments

Kaschny

Goñi

1992

European Journal of Biochemistry

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Spectral-data-processing and curve-fitting techniques have been applied to the decomposition of merocyanine-540 absorption spectra in aqueous, micellar and bilayer environments. The various resolved component bands have been assigned to dye monomers, dimers, or larger aggregates, either in polar or non-polar environments. The analysis of spectral parameters (A, , , and integrated intensity) of the overall spectra and of each component has revealed that merocyanine 540 is a useful probe in studies of membrane structure and dynamics using visible-absorption spectroscopy. In particular, the monomer A, ,, and the integrated intensity, i.e. area, of the dimer population are very useful in this respect. The monomer A, , , is especially sensitive to polarity changes and is thus useful, e.g. in the precise determination of critical micellar concentrations. The fractional area of the dimer increases with the packing density of the phospholipid-hydrocarbon region near the interface and is thus very sensitive to changes in vesicle curvature and to the presence of sterols or intrinsic polypeptides in the bilayer.Cyanine dyes have been frequently used as optical probes in membrane studies. In particular, the anionic dye merocyanine 540 (MCS40) has found widespread application [l]. Due to its amphipathic nature, MC540 ( Fig. 1) is soluble in solvents of a wide polarity range, including water and, to a limited extent, chloroform. The dye can easily be incorporated into the bilayer of phospholipid model membranes and partitions into the lipid phase when added externally to an aqueous liposome suspension [2,3]. MC540 exhibits an equilibrium between fluorescent monomers and non-fluorescing dimers which depends on the dispersing medium. In phospholipid bilayers the monomer chromophore is thought to be located near the membrane/water interface [3].The A, , , of the dye's visible spectrum correlates very well with the dielectric constant of the solvent [4]. This supports the use of MC540 as a solvatochromic dye; polarity changes in the microenvironment of the chromophore are monitored as I,,, shifts. Most important, however, is its ability to show variations in surface potential by changes in its absorbance and fluorescence spectra [ 5 , 61. The electrochromic properties of the dye are of particular interest when the object of study is too small to allow the application of microelectrodes. Furthermore, MC540 selectively stains leukemic and immature hemopoietic cells, also acting as a photosensitizing agent [7, 81. Correspondence to F. M. Go@ Department of Biochemistry, Faculty of Science, University of the Basque Country, Apartado 644, E-48080 Bilbao, SpainAbbreviations. CMC, critical micellar concentration; LUV, large unilamellar vesicles; MC540, merocyanine 540; MLV, multilamellar vesicles; PtdCho, phosphatidylcholine; SUV, small unilamellar vesicles.The versatility of the dye as an optical membrane probe explains the importance of a precise analysis of its spectrometric properties. This is particularly valid for the evaluation...

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Section: Factors Leading To Mc540 Dimerization In Membranessupporting

confidence: 63%

“…6B) can be correlated with the cholesterol-induced increase in lipid packing density. In a different context, cholesterol has been shown to reduce cell membrane staining by MC540 [21,27]. This is obviously a consequence of the sterolcondensing effect.…”

Section: Factors Leading To Mc540 Dimerization In Membranesmentioning

confidence: 99%

The components of merocyanine‐540 absorption spectra in aqueous, micellar and bilayer environments

Kaschny

Goñi

1992

European Journal of Biochemistry

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“…For personal use only. on May 12, 2018. by guest www.bloodjournal.org From Cell shrinkage and MC540 uptake by murine B cells MC540 is a fluorescent, lipophilic dye that binds preferentially to the outer leaflet of plasma membrane bilayers with relatively loosely packed lipids, 5,[18][19][20] including those of apoptotic cells. 6,7 We compared the kinetic relationship between MC540-binding (to measure lipid packing) and AV-binding (to measure PS exposure).…”

Section: Ps Translocation By B Cells Is Independent Of Abca1mentioning

confidence: 99%

Phosphatidylserine exposure in B lymphocytes: a role for lipid packing

Elliott

Sardini

Cooper

et al. 2006

Blood

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Plasma membrane lipids are usually distributed asymmetrically, with phosphatidylserine (PS) confined to the inner leaflet. PS exposure at the outer leaflet occurs early in apoptosis, but it is also constitutive on some nonapoptotic cell populations where it plays a role in cell signaling. How PS is transported ("flopped") to the cell surface is unknown. Contrary to previous reports that normal murine B lymphocytes lack lipid asymmetry, we show that PS is normally restricted to the inner leaflet of these cells. PS exposure on normal B cells did, however, occur spontaneously ex vivo. Consistent with the hypothesis that loss of PS asymmetry is regulated by CD45, PS is constitutively exposed on viable, CD45-deficient B cells. We show that calcium-stimulated PS exposure in B cells is strain variable, ABCA1 independent, and both preceded by and dependent on a decrease in lipid packing. This decrease in lipid packing is concomitant with cell shrinkage and consequent membrane distortion, both of which are potently inhibited by blockers of volumeregulatory K ؉ and Cl ؊ ion channels. Thus, changes in plasma membrane organization precede PS translocation. The data suggest a model in which PS redistribution may occur by a translocaseindependent mechanism at energetically favorable sites of membrane perturbation where lipid packing is decreased. (Blood.

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“…plasma membrane, as it is unable to penetrate the mem-MC + population could throw light on cell cycle kinetics brane of living cells (4,9). From the data shown in Table in leukemic cells by revealing differences that cannot be 1, we conclude that the MC f population contained the detected in the total population.…”

Section: ~ (3)mentioning

confidence: 84%

Selective staining of immature hemopoietic cells with merocyanine 540 in flow cytometry

et al. 1988

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Merocyanine 540 (MC540) has been reported to bind hemopoietic cells specifically. In this study, MC540 was used as a probe for the cytofluorometric discrimination of hemopoietic cells. In PHA‐stimulated lymphocytes or HL‐60 cells induced to differentiate with DMSO, MC540 binding was increased in actively proliferating cells and undifferentiated cells as compared with the more differentiated cells of the same lineage. Mononuclear bone marrow cells exhibited a discrete distribution of MC fluorescence. Sorting a population with high MC540 fluorescence (MC+ population) produced a 9–14‐fold enrichment of granulocyte‐macrophage progenitors (CFU‐GM), and a recovery of all S‐G2M phase cells (BrdUrd/DNA analysis). Cytological examination of the sorted MC+ population confirmed the enrichment in immature cells from all lineages. Double‐labeling experiments using MC540 and Hoechst 33342 on total bone marrow or peripheral blood cells confirmed that the MC+ population included all the cycling cells. The proportion of S‐G2M phase cells in this MC+ population was 29.3 ± 7.8 for 15 bone marrow samples and 16.3 ± 6.8 for 10 blood samples. MC540 could therefore be used as a marker for human hemopoietic cells, and it represents a useful tool for investigation of hemopoiesis in normal or leukemic bone marrow.

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Cholesterol-free phospholipid domains may be the membrane feature selected by Nε-dansyl-L-lysine and merocyanine 540

Cited by 44 publications

References 10 publications

The components of merocyanine‐540 absorption spectra in aqueous, micellar and bilayer environments

The components of merocyanine‐540 absorption spectra in aqueous, micellar and bilayer environments

Phosphatidylserine exposure in B lymphocytes: a role for lipid packing

Selective staining of immature hemopoietic cells with merocyanine 540 in flow cytometry

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