Dehydration of Hydrated Bilayer of Dipalmitoylphosphatidylcholine Caused by Beryllium Ion: Evidence from a Differential Scanning Calorimetry of Bilayer Phase Transition
✍ Scribed by Hideyuki Minami; Tohru Inoue
- Publisher
- Elsevier Science
- Year
- 1998
- Tongue
- English
- Weight
- 119 KB
- Volume
- 206
- Category
- Article
- ISSN
- 0021-9797
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✦ Synopsis
The effect of polyvalent metal ions Be 2؉ , Mg 2؉ , Ca 2؉ , Sr 2؉ , Ba 2؉ , and La 3؉ on the phase transition behavior of hydrated bilayer of dipalmitoylphosphatidylcholine (DPPC) was investigated by differential scanning calorimetry (DSC) in relation to their ability to induce the aggregation of DPPC vesicles. The addition of the metal ions other than Be 2؉ provided DSC thermograms characteristic to a fully hydrated DPPC bilayer. By the addition of Be 2؉ , the endothermic peak associated with the bilayer phase transition was shifted to that corresponding to partially dehydrated DPPC bilayer, which was reported by Kodama et al. (Biochem. Biophys. Acta 689, 567, 1982). This demonstrates that Be 2؉ causes dehydration of DPPC head group in hydrated bilayer and supports the speculation that the unusual property of Be 2؉ to induce the aggregation of PC vesicles is attributed to the destruction of repulsive hydration force due to the partial dehydration of vesicular surface.