| DOI | Resolve DOI: https://doi.org/10.1016/0005-2736(84)90297-9 |
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| Author | Search for: Mendelsohn, R.; Search for: Brauner, J. W.; Search for: Faines, L.; Search for: Mantsch, H. H.1; Search for: Dluhy, R. A.1 |
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| Affiliation | - National Research Council of Canada
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| Format | Text, Article |
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| Subject | Lipid-protein interaction; Phase transition; Infrared spectroscopy; Calorimetry; Glycophorin; Phospholipid vesicle |
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| Abstract | Glycophorin has been isolated in pure form from human erythrocyte membranes and reconstituted into lipid vesicles composed of binary mixtures of bovine brain phosphatidylserine (PS) and acyl-chain perdeuterated dipalmitoyiphosphatidylcholine (DPPC-d₆₂). The effect of protein on lipid melting behavior and order has been monitored with differential scanning calorimetry and Fourier transform infrared spectroscopy (FT-IR). The phase diagram for PS/DPPC-d₆₂ is consistent with that previously reported for PS/DPPC (Stewart et al. (1979) Biochim. Biophys. Acta 556, 1-16) and indicates that acyl chain perdeuteration does not greatly alter the lipid mixing characteristics. The use of deuterated lipid allows the examination of lipid order by FT-IR of each lipid component in the binary mixtures as well as in the ternary (lipid/lipid/protein) systems. Addition of glycophorin to a 30:70 PS/DPPC-d₆₂ binary lipid mixture results in a preferential glycophorin/PS interaction leading to bulk lipid enriched in DPPC-d₆₂. This is revealed in two ways: first, through cooperative calorimetric transitions increased in temperature from the binary lipid system and second, through FT-IR melting curves of the DPPC-d₆₂ component which shows transitions increased in both onset and completion temperatures in the presence of protein. In addition, non-cooperative melting events are observed at temperatures below the onset of phase separation. The FT-IR data are used to assign these non-cooperative events to the melting of the PS component. For the 50:50 lipid mixture with protein, two transitions are observed in the DSC experiments. The IR results indicate that both lipid components are involved with the lower temperature event. |
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| Publication date | 1984-07-25 |
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| In | |
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| Language | English |
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| Peer reviewed | Yes |
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| NPARC number | 23001264 |
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| Export citation | Export as RIS |
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| Report a correction | Report a correction (opens in a new tab) |
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| Record identifier | 082bd141-a58e-4d8c-b725-37b4d8b7503d |
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| Record created | 2017-01-12 |
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| Record modified | 2020-03-13 |
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