Thermal behavior of stearoylsphingomyelin-cholesterol dispersions.
Biochemistry
; 20(25): 7115-8, 1981 Dec 08.
Article
en En
| MEDLINE
| ID: mdl-7317370
The thermotropic behavior of aqueous dispersions of stearoylsphingomyelin-cholesterol mixtures was examined by high-sensitivity differential scanning calorimetry. When less than 20 mol % cholesterol was mixed with the sphingomyelin and the samples were held at room temperature for 7-9 days before the initiation of calorimetric measurements, a sharp endotherm at 56-57 degrees C and a broad endotherm at 35-50 degrees C were observed. In addition, samples containing 15-20 mol % stearol exhibited a sharp endotherm at 43-45 degrees C. If samples were held at room temperature for less than 2 h before the initiation of calorimetric analysis, the 56-57 degrees C endotherm was usually not seen. Instead, a combination of broad and sharp endotherms over the range of 35-50 degrees C was observed. Occasionally, exotherms were also observed within this temperature range. These results, along with those from previous studies, imply that a cholesterol-rich phase coexists with a cholesterol-poor phase in which the sphingomyelin molecules may exist in two distinctly different gel states.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Esfingomielinas
/
Colesterol
/
Liposomas
Idioma:
En
Revista:
Biochemistry
Año:
1981
Tipo del documento:
Article
Pais de publicación:
Estados Unidos