Intrinsic molecules in lipid membranes change the lipid-domain interfacial area: cholesterol at domain interfaces

Cruzeiro, Leonor; Ipsen, John Hjort; Mouritsen, Ole G.

doi:10.1016/0005-2736(89)90432-x

Cited by 86 publications

(45 citation statements)

References 35 publications

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“…This overlapping between the MGDG head groups could induce the formation of local instabilities, improving the insertion of the protein in the film. 41,42 In a previous study, we have shown that, for the same surface pressure, the DGDG occupied a smaller mean molecular area than MGDG, suggesting that the galactosyl groups closely interact in the aqueous subphase. 25 This could prevent PIN-a from deep insertion into the DGDG monolayer.…”

Section: Discussionmentioning

confidence: 96%

Structure and Orientation of Puroindolines into Wheat Galactolipid Monolayers

et al. 2008

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Puroindolines (PINs), basic and cysteine-rich proteins of wheat endosperm, are composed of two proteins, puroindoline-a (PIN-a) and puroindoline-b (PIN-b). Using a monolayer assay at the air/liquid interface, both PIN-a and PIN-b were studied in pure components and mixed with wheat galactolipids, 1,2-di-O-acyl-3-O-(beta-d-galactopyranosyl)- sn-glycerol (MGDG) and 2-di-O-acyl-3-O-(beta-d-galactopyranosyl-1,6-beta-d-galactopyranosyl)-sn-glycerol (DGDG). Following the adsorption of PINs at the air/liquid interface thanks to surface pressure increases, we concluded that PIN-a displays a more amphipathic character than PIN-b. Compression isotherms combined with ellipsometric measurements showed that the area per molecule is smaller and the protein film is more condensed for PIN-a than for PIN-b. According to the polarization modulation-infrared reflection-absorption spectroscopy data, both proteins display a highly alpha-helical structure and the alpha-helices are oriented rather parallel to the interface. By measuring the overpressure due to PIN adsorption into MGDG and DGDG monolayers, we observed that PIN-a interacts more strongly into lipid films than PIN-b. The observation by atomic force microscopy of mixed protein/lipid films showed that the nature of the lipid plays a significant role in the organization of PINs, particularly for PIN-a. The presence of galactolipids at the interface stabilizes the alpha-helical structure of PINs, but significant changes were observed concerning the orientation of the alpha-helices. They adopt a perfect parallel orientation to the interface in the MGDG monolayer, whereas the bundle of alpha-helices orients normal to the interface in the DGDG film.

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Section: Discussionmentioning

confidence: 96%

Structure and Orientation of Puroindolines into Wheat Galactolipid Monolayers

et al. 2008

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“…The behaviour vs. wavelength is qualitatively similar to that observed in the liquid-crystalline phase and quite different from that observed in the presence of coexisting domains of the two phases. Several recent articles reported on the progressive removal of phospholipid phase transition by cholesterol addition [32][33][34]. Many groups are concerned with the occurrence of phospholipid domains containing different cholesterol concentrations in model systems [21][22][23][24]35,36].…”

Section: Discussionmentioning

confidence: 99%

Absence of lipid gel-phase domains in seven mammalian cell lines and in four primary cell types

Parasassi

Loiero

Raimondi

et al. 1993

Biochimica et Biophysica Acta (BBA) - Biomembranes

100

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“…2d showing a heterogeneity of SM domains were previously obtained in DPPC/DOPC films containing 4% of the ganglioside GM 1 [33]. They most likely correspond to a gel-gel phase separation between SM species with the longest saturated species forming the included round shape domains and concentrating at the gel-fluid interface thus decreasing the interfacial tension [34]. In what concerns the globular domains, their existence likely results from two-dimensional relaxation processes within a highly frustrated bilayer in the gel state.…”

Section: Article In Pressmentioning

confidence: 97%