The Binding of Aβ42 Peptide Monomers to Sphingomyelin/Cholesterol/Ganglioside Bilayers Assayed by Density Gradient Ultracentrifugation

International Journal of Molecular Sciences

Hasna Ahyayauch¹  Igor de la Arada¹  JoséL. R. Arrondo¹  Alicia Alonso¹  FélixM. Goñi¹  MassimoE. Masserini² 

[1] Instituto Biofisika (CSIC, UPV/EHU) and Departamento de Bioquímica, Universidad del País Vasco, 48080 Bilbao, Spain;School of Medicine and Surgery, University of Milano-Bicocca, 20900 Monza, Italy;

关键词: aβ42;    beta-amyloid;    membrane binding;    density gradient ultracentrifugation;    ganglioside;    sphingomyelin;    cholesterol;   

DOI  :  10.3390/ijms21051674

来源: DOAJ

【 摘 要 】

The binding of Aβ42 peptide monomers to sphingomyelin/cholesterol (1:1 mol ratio) bilayers containing 5 mol% gangliosides (either GM1, or GT1b, or a mixture of brain gangliosides) has been assayed by density gradient ultracentrifugation. This procedure provides a direct method for measuring vesicle-bound peptides after non-bound fraction separation. This centrifugation technique has rarely been used in this context previously. The results show that gangliosides increase by about two-fold the amount of Aβ42 bound to sphingomyelin/cholesterol vesicles. Complementary studies of the same systems using thioflavin T fluorescence, Langmuir monolayers or infrared spectroscopy confirm the ganglioside-dependent increased binding. Furthermore these studies reveal that gangliosides facilitate the aggregation of Aβ42 giving rise to more extended β-sheets. Thus, gangliosides have both a quantitative and a qualitative effect on the binding of Aβ42 to sphingomyelin/cholesterol bilayers.

【 授权许可】

Unknown