Artículos de revistas
Factors determining detergent resistance of erythrocyte membranes
Fecha
2008-04Registro en:
Rodi, Pablo Marcelo; Trucco, Verónica Milagros; Gennaro, Ana Maria; Factors determining detergent resistance of erythrocyte membranes; Elsevier Science; Biophysical Chemistry; 135; 1-3; 4-2008; 14-18
0301-4622
CONICET Digital
CONICET
Autor
Rodi, Pablo Marcelo
Trucco, Verónica Milagros
Gennaro, Ana Maria
Resumen
The degree of detergent insolubility of cell membranes is a useful parameter to test the strength of lipid–lipid interactions relative to lipid–detergent interactions. Thus, solubility studies could give insights about lipid–lipid interactions relevant in domain formation. In this work we perform a detailed study of the solubilization of four different erythrocyte membrane systems: intact human and bovine erythrocytes, and human and bovine erythrocytes depleted in cholesterol with methyl-â-cyclodextrin. Each system was incubated with different concentrations of the non-ionic detergent Triton X-100, and the insoluble fraction was characterized by determining cholesterol and phosphorus content. A distinct solubilization behavior was obtained for the four systems, which was quantified by a “detergent resistance parameter” obtained from the fit of the solubility curves. In order to correlate these findings with membrane structural parameters, we quantify the degree of acyl chain order/rigidity of the original membranes by EPR spectroscopy, finding that detergent resistance is higher when acyl chains are more rigid. Regarding compositional properties, we found a good correlation between detergent resistance parameters and the total amount of cholesterol plus sphingomyelin in the original membranes. Our results suggest that a high degree of acyl chain packing is the determinant membrane factor for resistance to the action of Triton X-100 in erythrocytes.