Differential scanning calorimetry of the triphosphoinositide-water system
1991; Elsevier BV; Volume: 183; Linguagem: Inglês
10.1016/0040-6031(91)80467-w
ISSN1872-762X
AutoresToshiharu Takizawa, Kohei Hayashi, Hiroshi Mitomo,
Tópico(s)Erythrocyte Function and Pathophysiology
ResumoTriphosphoinositide (TPI) (Phosphatidylinositol-4,5-bis-(phosphate) (PIP2)) is an acidic phospholipid occurring at high levels in nerve tissues, which has attracted special interest concerning nerve excitation and cell signalling. In our differential scanning calorimetric study of the PIP2-water system and a broad endothermal peak was observed. The transitional enthalpy increases rapidly with an increase in the ratio of water to PIP2. The endothermal transition displays a strong hysteresis in the heating and cooling cycles in differential scanning calorimetry. An NMR study of an aqueous dispersion of PIP2 revealed that the endothermal transition cannot be attributed to a gel to liquid-crystal transformation. We postulated a thermal dehydration mechanism for the PIP2 -water system, based on the model of the internally hydrated PIP2 bilayer reported in a previous paper.
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