In two-component phosphatidylcholine bilayers with coexisting liquid and P beta' gel phases, the distribution between phases of low concentrations of glycosphingolipids can be determined by freeze-etch electron microscopy after labeling the glycolipid with a suitable protein. We have found that the distribution depends upon the glycosphingolipid species (Rock, P. et al., (1991) Biochemistry 30, 19-25). Using this technique with cholera toxin as the protein label and bilayers formed from dipalmitoyl- and dielaidoylphosphatidylcholine (1:1) containing < 1 mol% GM1, we have studied the distribution of a family of GM1 homologues differing in the acyl chain and sphingoid base moieties. The GM1 preference for the P beta' ripple phase decreases with decreasing acyl chain length and increasing unsaturation. GM1 with either a C18:1 or C20:1 sphingoid base shows similar distributions in liquid and gel phases. When the molecules are preferentially found in the P beta' phase, they are positioned along unique loci in both A and A/2 forms of the ripple structure. This localization and acyl chain dependence reflect the volume, shape and localization of molecular packing defects in the P beta' phase. The ganglioside inclusions stabilize the P beta' phase and form compositional domains of unique topography

Palestini, P., Allietta, M., Sonnino, S., Tettamanti, G., Thompson, T., & Tillack, T. (1995). Gel phase preference of ganglioside GM1 at low concentration in two-component, two-phase phosphatidylcholine bilayers depends upon the ceramide moiety. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES, 1235(2), 221-230 [10.1016/0005-2736(95)80008-4].

Gel phase preference of ganglioside GM1 at low concentration in two-component, two-phase phosphatidylcholine bilayers depends upon the ceramide moiety

Palestini, PNA;
1995

Abstract

In two-component phosphatidylcholine bilayers with coexisting liquid and P beta' gel phases, the distribution between phases of low concentrations of glycosphingolipids can be determined by freeze-etch electron microscopy after labeling the glycolipid with a suitable protein. We have found that the distribution depends upon the glycosphingolipid species (Rock, P. et al., (1991) Biochemistry 30, 19-25). Using this technique with cholera toxin as the protein label and bilayers formed from dipalmitoyl- and dielaidoylphosphatidylcholine (1:1) containing < 1 mol% GM1, we have studied the distribution of a family of GM1 homologues differing in the acyl chain and sphingoid base moieties. The GM1 preference for the P beta' ripple phase decreases with decreasing acyl chain length and increasing unsaturation. GM1 with either a C18:1 or C20:1 sphingoid base shows similar distributions in liquid and gel phases. When the molecules are preferentially found in the P beta' phase, they are positioned along unique loci in both A and A/2 forms of the ripple structure. This localization and acyl chain dependence reflect the volume, shape and localization of molecular packing defects in the P beta' phase. The ganglioside inclusions stabilize the P beta' phase and form compositional domains of unique topography
Articolo in rivista - Articolo scientifico
Freeze Etching; Ceramides; Liposomes; Animals; Phosphatidylcholines; Gels; Cattle; Lipid Bilayers; Microscopy, Electron; Cholera Toxin; Molecular Sequence Data; Carbohydrate Sequence; G(M1) Ganglioside
English
221
230
10
Palestini, P., Allietta, M., Sonnino, S., Tettamanti, G., Thompson, T., & Tillack, T. (1995). Gel phase preference of ganglioside GM1 at low concentration in two-component, two-phase phosphatidylcholine bilayers depends upon the ceramide moiety. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES, 1235(2), 221-230 [10.1016/0005-2736(95)80008-4].
Palestini, P; Allietta, M; Sonnino, S; Tettamanti, G; Thompson, T; Tillack, T
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/10281/21478
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