Interaction of α-lactalbumin with dimyristoylphosphatidylcholine vesicles. III. Influence of the temperature and of the lipid-to-protein molar ratio on the complex formation

Hanssens, Ignace; Herreman, W.; Ceunebroeck, Jean-Claude Van; Dangreau, Hugo; Gielens, Constant; Préaux, Gisèle; Cauwelaert, Frans Van

doi:10.1016/0005-2736(83)90498-4

Cited by 17 publications

(4 citation statements)

References 23 publications

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“…This observation clearly favors that both DMPC and DPPC were present in every bilayer of the sedimented DMPC/DPPC vesicles obtained after their sonication at a temperature between the DMPC and DPPC Tm's. This was confirmed by recent data obtained from experiments based on the strange property of a-lactalbumin to disrupt phospholipid vesicles at pH 4 only when incubated at a temperature close to the phospholipid bilayer Tm (Hanssens et al, 1983). Sedimented DMPC/DPPC vesicles obtained after sonication at a temperature intermediate between DMPC Tm and DPPC Tm could be fully disrupted after their incubation with a-lactalbumin at a temperature close to the DMPC Tm or to the DPPC Tm (data not shown).…”

Section: Resultssupporting

confidence: 85%

Phase separation of miscible phospholipids by sonication of bilayer vesicles

Bakouche¹,

Gerlier²,

Létoffé³

et al. 1986

Biophysical Journal

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Sonication of phospholipid vesicles may result, according to their liquid or solid crystal state, in the generation of unilamellar vesicles or structural defects within their bilayers, respectively. The transition temperature Tm of the phospholipid bilayer is usually the threshold temperature delineating the physical effects of ultrasound. However, for vesicles made from a mixture of two miscible phospholipids, this threshold temperature was not found to be the intermediate Tm of the phospholipid mixture bilayers, but the Tm of the lowest melting component. This was due to a simultaneous lateral phase separation of the two phospholipids induced by the sonication as demonstrated by differential scanning calorimetry analysis.

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Section: Resultssupporting

confidence: 85%

Phase separation of miscible phospholipids by sonication of bilayer vesicles

Bakouche¹,

Gerlier²,

Létoffé³

et al. 1986

Biophysical Journal

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“…The molten globule conformation of -lactalbumin (a-LA)1 has been studied extensively (Alexandrescu et al, 1993;Dolgikh et al, 1981Dolgikh et al, , 1985Kuwajima, 1989). The interactions of -LA with lipid membranes have also been studied (Hanssens et al, 1980(Hanssens et al, , 1983(Hanssens et al, , 1985Hanssens & Van Cauwelaert, 1978;Herreman et al, 1981; Kim & Kim, 1986, 1989Van Cauwelaert et al, 1983). It has been shown, both in monolayers at the air-water interface and in bilayer membranes (Hanssens et al, 1980(Hanssens et al, , 1985, that -LA interacts with the polar head groups of PC in the native state at pH 7.…”

mentioning

confidence: 99%

Interaction of .alpha.-Lactalbumin with Phosphatidylglycerol. Influence of Protein Binding on the Lipid Phase Transition and Lipid Acyl Chain Mobility

Montich

Marsh

1995

Biochemistry

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The mobility of spin-labeled lipids has been studied in dioleoyl and dimyristoyl phosphatidylglycerol bilayers and in their complexes with alpha-lactalbumin at pH 4.0, by using electron spin resonance (ESR) spectroscopy. The ESR spectra of phosphatidylglycerol spin-labeled at position 5 of the sn-2 chain indicate that association of alpha-lactalbumin with dimyristoyl phosphatidylglycerol bilayers increases the chain mobility at temperatures in the lipid gel phase, restricts the chain mobility at temperatures corresponding to the lipid fluid phase, and abolishes the cooperative lipid chain-melting transition. The ESR spectra of phosphatidylglycerols spin-labeled at eight different positions in the sn-2 chain show that binding of alpha-lactalbumin to dioleoyl phosphatidylglycerol bilayers at pH 4.0 causes a motional restriction throughout the full length of the lipid acyl chain. For phosphatidylglycerols spin-labeled at the terminal methyl end of the chains, a population of motionally restricted lipids that directly contacts membrane penetrant portions of the protein is detected. This population corresponds to 6.3 +/- 0.7 lipids/alpha-lactalbumin at saturation binding, and the high degree of motional restriction (maximum hyperfine splitting approximately 60 G) suggests that the protein may traverse the lipid bilayer. A small selectivity of phosphatidylglycerol over zwitterionic phospholipids for interaction with alpha-lactalbumin is found at subsaturating levels of binding at pH 4.0. Binding of alpha-lactalbumin also strongly restricts the motion of lipids spin-labeled in the polar head group region. These results are of direct relevance to the insertion and translocation of a protein in the molten globule state across lipid membranes.

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“…It has been observed that a-lactalbumin and dimyristoyl phosphatidylcholine (DMPC) vesicles do not form a complex at pH 7.0. The protein behaves as uncomplexed protein, and the vesicles keep their original dimensions [32]. Our results suggest that similar to DMPC, DPPC also does not undergo any complexation in presence of a-lactalbumin, as there is no significant change in the thermodynamic parameters.…”

Section: Differential Scanning Calorimetric Studies On Thermal Transimentioning

confidence: 58%

Thermodynamics of α-lactalbumin–dl-α-dipalmitoylphosphatidylcholine interactions and effect of the antioxidant nicotinamide on these interactions

Kundu

Kishore

2005

Biophysical Chemistry

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Interaction of α-lactalbumin with dimyristoylphosphatidylcholine vesicles. III. Influence of the temperature and of the lipid-to-protein molar ratio on the complex formation

Cited by 17 publications

References 23 publications

Phase separation of miscible phospholipids by sonication of bilayer vesicles

Phase separation of miscible phospholipids by sonication of bilayer vesicles

Interaction of .alpha.-Lactalbumin with Phosphatidylglycerol. Influence of Protein Binding on the Lipid Phase Transition and Lipid Acyl Chain Mobility

Thermodynamics of α-lactalbumin–dl-α-dipalmitoylphosphatidylcholine interactions and effect of the antioxidant nicotinamide on these interactions

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