Sphingomyelin Structure Influences the Lateral Diffusion and Raft Formation in Lipid Bilayers

Филиппов, А. В.; Orädd, Greger; Lindblom, Göran

doi:10.1529/biophysj.105.075150

Cited by 98 publications

(84 citation statements)

References 46 publications

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“…This further supports the idea that SM (together with CHOL) has an additional role in rigidifying the bilayer and consequently slowing down diffusion. For comparison, a recent pulsed-field gradient NMR study [44] [45] also supports the idea that bilayers S A and S B do display the l o phase. Clearly, diffusion within raft domains is strongly suppressed due to the presence of PSM and CHOL.…”

Section: Author Summarymentioning

confidence: 73%

Assessing the Nature of Lipid Raft Membranes

Niemela¹,

Ollila²,

Hyvönen³

et al. 2005

PLoS Comput Biol

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Section: Author Summarymentioning

confidence: 73%

Assessing the Nature of Lipid Raft Membranes

Niemela¹,

Ollila²,

Hyvönen³

et al. 2005

PLoS Comput Biol

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“…In particular, egg sphingomyelin has a phase transition centered around 39 1C (ref. 33), whereas individual sphingomyelin species melt above 40 1C (ref. 34).…”

Section: Discussionmentioning

confidence: 99%

Progressive ordering with decreasing temperature of the phospholipids of influenza virus

Polozov¹,

Bezrukov²,

Gawrisch³

et al. 2008

Nat Chem Biol

200

159

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Using linewidth and spinning sideband intensities of lipid hydrocarbon chain resonances in proton magic angle spinning NMR spectra, we detected the temperature-dependent phase state of naturally occurring lipids of intact influenza virus without exogenous probes. Increasingly, below 41 1C ordered and disordered lipid domains coexisted for the viral envelope and extracts thereof. At 22 1C much lipid was in a gel phase, the fraction of which reversibly increased with cholesterol depletion. Diffusion measurements and fluorescence microscopy independently confirmed the existence of gel-phase domains. Thus the existence of ordered regions of lipids in biological membranes is now demonstrated. Above the physiological temperatures of influenza infection, the physical properties of viral envelope lipids, regardless of protein content, were indistinguishable from those of the disordered fraction. Viral fusion appears to be uncorrelated to ordered lipid content. Lipid ordering may contribute to viral stability at lower temperatures, which has recently been found to be critical for airborne transmission.Membranes of most enveloped viruses form by budding out from the plasma membranes of their host cells a highly select subset of plasma membrane components. In general, the selected membrane proteins are coded by the viral genome, whereas lipids are recruited from host membranes; however, the lipid composition of the viral envelope differs from that of the host membrane 1,2 and from other budding viruses 3 . The envelope of influenza contains higher amounts of both cholesterol 1 and glycosphingolipids 4 -lipids known to partition into the liquid ordered (l o ) phase. The l o phase is characterized by extended hydrocarbon chains having a reduced gauche-trans isomerization compared with those of the liquid disordered (l d ) phase, but having a similar rotational and translational mobility 5 . Liquid ordered phases are thought to be at the core of lipid rafts 6 , which are defined as transient membrane microdomains that are enriched in sphingolipids and cholesterol (1) 7 -a hypothesis that has generated much debate 8,9 .The influenza virus has played a pivotal role in the development of the raft hypothesis, starting with early studies that inferred ordered domains using spin probes 10-12 and fluorescence 13,14 and that suggested that an ordered lipid domain is selected in toto as the envelope during budding from the plasma membrane 15 . These lipids are either selected at the time of budding or pre-selected as the 'pre-envelope' suggested by clusters of the viral envelope protein hemagglutinin seen in immunoelectron microscopy 16 .Although detection of virus-sized domains of lipids (B100-nm diameter) is below the limit of resolution of fluorescent microscopy, large micrometer-sized membrane domains are reliably detected [17][18][19] . Recently, proton magic angle spinning NMR ( 1 H MAS NMR) has been used to determine the phase diagram of the same lipid compositions used to study large membrane domains in lipid bilayers and othe...

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“…The main fluid to gel transition of these extracts in excess water have been studied previously by differential scanning 60 calorimetry 8 and the transition temperatures are summarised in Table 1. It should be noted that as these are mixtures of different chain length lipids, the transition tends to be rather broad and melting occurs over a significant temperature range.…”

Section: Introductionmentioning

confidence: 99%

Pressure–temperature phase behaviour of natural sphingomyelin extracts

et al. 2012

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Sphingomyelin is the only sphingolipid occurring naturally in mammalian cells and can form up to 50% of the total phospholipid content of the myelin sheath which surrounds nerves. Having predominantly long, saturated acyl chains, it has a relatively high chain melting temperature and has been strongly associated with formation of lipid microdomains. Here, the lyotropic phase behaviour of sphingomyelin 10 from three different natural sources (bovine brain, egg yolk and milk) in excess water is studied as a function of temperature and pressure by small-and wide-angle X-ray scattering, and solid state NMR. The different hydrocarbon chain length distributions of the three lipid extracts results in significant differences in their gel phase structure; both the bovine brain and egg yolk sphingomyelins can form a ripple gel phase but milk sphingomyelin forms an interdigitated gel phase due to the high degree of chain 15 mismatch in its longer hydrocarbon chain components.

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Sphingomyelin Structure Influences the Lateral Diffusion and Raft Formation in Lipid Bilayers

Cited by 98 publications

References 46 publications

Assessing the Nature of Lipid Raft Membranes

Assessing the Nature of Lipid Raft Membranes

Progressive ordering with decreasing temperature of the phospholipids of influenza virus

Pressure–temperature phase behaviour of natural sphingomyelin extracts

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