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(Referência obtida automaticamente do Web of Science, por meio da informação sobre o financiamento pela FAPESP e o número do processo correspondente, incluída na publicação pelos autores.)

Resistance of Human Erythrocyte Membranes to Triton X-100 and C12E8

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Autor(es):
Crepaldi Domingues, Cleyton [1] ; Ciana, Annarita [2] ; Buttafava, Armando [3] ; Balduini, Cesare [2] ; de Paula, Eneida [1] ; Minetti, Giampaolo [2]
Número total de Autores: 6
Afiliação do(s) autor(es):
[1] Univ Estadual Campinas, Inst Biol, Dept Bioquim, Campinas, SP - Brazil
[2] Univ Pavia, Dipartimento Biochim A Castellani, I-27100 Pavia - Italy
[3] Univ Pavia, Dipartimento Chim Gen, I-27100 Pavia - Italy
Número total de Afiliações: 3
Tipo de documento: Artigo Científico
Fonte: Journal of Membrane Biology; v. 227, n. 1, p. 39-48, JAN 2009.
Citações Web of Science: 16
Resumo

Lipid rafts are microdomains enriched in cholesterol and sphingolipids that contain specific membrane proteins. The resistance of domains to extraction by nonionic detergents at 4A degrees C is the commonly used method to characterize these structures that are operationally defined as detergent-resistant membranes (DRMs). Because the selectivity of different detergents in defining membrane rafts has been questioned, we have compared DRMs from human erythrocytes prepared with two detergents: Triton X-100 and C(12)E(8). The DRMs obtained presented a cholesterol/protein mass ratio three times higher than in the whole membrane. Flotillin-2 was revealed in trace amounts in DRMs obtained with C(12)E(8), but it was almost completely confined within the DRM fraction with Triton X-100. Differently, stomatin was found distributed in DRM and non-DRM fractions for both detergents. We have also measured the order parameter (S) of nitroxide spin labels inserted into DRMs by means of electron paramagnetic resonance. The 5- and 16-stearic acid spin label revealed significantly higher S values for DRMs obtained with either Triton X-100 or C(12)E(8) in comparison to intact cells, while the difference in the S values between Triton X-100 and C(12)E(8) DRMs was not statistically significant. Our results suggest that although the acyl chain packing is similar in DRMs prepared with either Triton X-100 or C(12)E(8) detergent, protein content is dissimilar, with flotillin-2 being selectively enriched in Triton X-100 DRMs. (AU)

Processo FAPESP: 03/02394-4 - Solubilização de lipídios e proteínas de membrana por tensoativos clássicos e não clássicos
Beneficiário:Eneida de Paula
Modalidade de apoio: Auxílio à Pesquisa - Regular