Support for the shape concept of lipid structure based on a headgroup volume approach

Lee, Yang-Chih; Taraschi, Theodore F.; Janes, Nathan

doi:10.1016/s0006-3495(93)81206-2

Cited by 49 publications

(37 citation statements)

References 13 publications

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“…The aim of the current study was to directly measure the spontaneous curvature (the inverse of the spontaneous radius of curvature) of PA and LPA at a physiological pH and salt concentration. Our study extends previous more qualitative studies on the molecular shape of (L)PA (21)(22)(23)(24), and now allows theoretical models of biomembrane fission to be developed (3,16). We show that, under physiological conditions of pH and ionic strength, PA has a negative spontaneous curvature that is slightly less pronounced than that of dioleoylphosphatidylethanolamine (DOPE), while LPA has a spontaneous curvature that is considerably more positive than that of lysophosphatidylcholine (LPC).…”

supporting

confidence: 77%

Spontaneous Curvature of Phosphatidic Acid and Lysophosphatidic Acid

et al. 2005

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The formation of phosphatidic acid (PA) from lysophosphatidic acid (LPA), diacylglycerol, or phosphatidylcholine plays a key role in the regulation of intracellular membrane fission events, but the underlying molecular mechanism has not been resolved. A likely possibility is that PA affects local membrane curvature facilitating membrane bending and fission. To examine this possibility, we determined the spontaneous radius of curvature (R 0p ) of PA and LPA, carrying oleoyl fatty acids, using well-established X-ray diffraction methods. We found that, under physiological conditions of pH and salt concentration (pH 7.0, 150 mM NaCl), the R 0p values of PA and LPA were -46 Å and +20 Å, respectively. Thus PA has considerable negative spontaneous curvature while LPA has the most positive spontaneous curvature of any membrane lipid measured to date. The further addition of Ca 2+ did not significantly affect lipid spontaneous curvature; however, omitting NaCl from the hydration buffer greatly reduced the spontaneous curvature of PA, turning it into a cylindrically shaped lipid molecule (R 0p of -1.3 × 10 2 Å). Our quantitative data on the spontaneous radius of curvature of PA and LPA at a physiological pH and salt concentration will be instrumental in developing future models of biomembrane fission.

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confidence: 77%

Spontaneous Curvature of Phosphatidic Acid and Lysophosphatidic Acid

et al. 2005

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“…Indeed, we detected membrane tethering in the absence of nucleotides, suggesting that neither GTP nor ATP are required for this process. Nevertheless, the intrinsic negative curvature of the lipids correlated with Drp1 membrane-tethering activity (PA Ͼ CL Ͼ PG Ϸ PS), suggesting that non-lamellar membrane fission intermediates seemed to be involved, as also observed for vesicle aggregation (30,51,72).…”

Section: Discussionmentioning

confidence: 67%

Dynamin-related Protein 1 (Drp1) Promotes Structural Intermediates of Membrane Division

Ugarte‐Uribe

Müller

Otsuki

et al. 2014

Journal of Biological Chemistry

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Background: Drp1 mediates mitochondrial division via a poorly understood mechanism. Results: Drp1 promotes giant vesicle tethering and concentrates at contact sites in structures similar to those found in dividing mitochondria. Conclusion: Besides membrane constriction, Drp1 stabilizes structural intermediates of membrane division. Significance: This new role of Drp1 helps us understand mitochondrial biology.

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“…Both POPG and POPS contain negatively charged headgroups. The former, however, contains a smaller headgroup, yielding a more conical shape to the molecule, in contrast to the more cylindrical shape of POPS (Lee et al, 1993). The overall shape of a phospholipid, determined by the relative volume of the polar headgroup to the hydrophobic acyl chains, can influence the packing energetics of the bilayer and the activity of embedded membrane proteins (Gruner, 1985;Lundbaek et al, 1996;Stubbs and Slater, 1996), as discussed below.…”

Section: Phospholipid Headgroup Size Is a Critical Molecular Determinmentioning

confidence: 99%

“…Given a defined headgroup structure, phospholipid molecular shape becomes more conical with an increase in acyl chain unsaturation because of an increase in hydrophobic volume (Gruner, 1985;Lee et al, 1993). Thus, we evaluated EtOH action in bilayers containing two monounsaturated acyl (oleoyl) chains.…”

Section: Downloaded Frommentioning

confidence: 99%

Distinct Structural Features of Phospholipids Differentially Determine Ethanol Sensitivity and Basal Function of BK Channels

Crowley

Treistman²,

Dopico

2005

Molecular Pharmacology

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Large conductance Ca 2ϩ -activated K ϩ (BK) channel activity and its potentiation by ethanol are both critically modulated by bilayer phosphatidylserine (PS), a phospholipid involved in membrane-bound signaling. Whether PS is uniquely required for ethanol to modify channel activity is unknown. Furthermore, the structural determinants in membrane phospholipid molecules that control alcohol action remain to be elucidated. We addressed these questions by reconstituting BK channels from human brain (hslo) into bilayers that contained phospholipids differing in headgroup size, charge, and acyl chain saturation. Data demonstrate that ethanol potentiation of hslo channels is blunted by conical phospholipids but favored by cylindrical phospholipids, independently of phospholipid charge. As found with ethanol action, basal channel activity is higher in bilayers containing cylindrical phospholipids. Basal activity and its ethanol potentiation in bilayers containing phosphatidylcholine, however, are not as robust as in those containing PS. These results are best interpreted as resulting from the relief of bilayer stress caused by inclusion of cylindrical phospholipids, with this relief being synergistically evoked by molecular shape and negative headgroup charge. Present findings suggest that hslo gating structures targeted by ethanol are accessible to sense changes in bilayer stress. In contrast, hslo unitary conductance is significantly higher in bilayers that contain negatively charged phospholipids independently of molecular shape, a result that is likely to be dependent on an interaction between anionic phospholipids and deep channel residues coupled to the selectivity filter.Large conductance, Ca 2ϩ -activated K ϩ (BK) channels play a pivotal role in both the behavioral response to acute EtOH exposure (Davies et al., 2003) and the cell adaptations that accompany protracted drug administration (Knott et al., 2002). BK channel activity in neurons and neuroendocrine cell types is usually potentiated by EtOH (Dopico et al., 1996(Dopico et al., , 1999Jakab et al., 1997;Knott et al., 2002;Martin et al., 2004). However, EtOH potentiation of BK channels is not universal. In hormone-releasing supraoptic neurons, nerve terminal BK channels are potentiated by EtOH, whereas cell body BK channels are refractory to similar concentrations of the drug (Dopico et al., 1999). Furthermore, BK channels from vascular tissues are primarily inhibited by EtOH (Walters et al., 2000;Liu et al., 2003Liu et al., , 2004b. Experimental conditions make it unlikely that the reported differences in EtOH action on BK channels can be explained by differential modulation of drug action by cytosolic messengers. Differences in EtOH action on BK channels across different tissues and cell domains may be orchestrated by a variety of molecular mechanisms, including expression of different isoforms Preliminary data were presented at the 33rd ABBREVIATIONS: BK channel, large conductance Ca 2ϩ -activated K ϩ channel; POPE, 1-palmitoyl-2-oleoyl-phosphati...

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Support for the shape concept of lipid structure based on a headgroup volume approach

Cited by 49 publications

References 13 publications

Spontaneous Curvature of Phosphatidic Acid and Lysophosphatidic Acid

Spontaneous Curvature of Phosphatidic Acid and Lysophosphatidic Acid

Dynamin-related Protein 1 (Drp1) Promotes Structural Intermediates of Membrane Division

Distinct Structural Features of Phospholipids Differentially Determine Ethanol Sensitivity and Basal Function of BK Channels

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