Association of endogenous IDE with DRMs is sensitive to membrane-lipid composition. A-Sucrose gradient fractions from N2aWT cells control (CTL), treated with MβCD alone (MβCD) or replenished with soluble Chol (MβCD + Chol) analysed by western blotting with anti-IDE and anti-flotillin-1 antibodies, respectively. Framed region, DRMs (fractions 3 and 4). B- Bars showed the percentage of total endogenous IDE and flotillin-1 in sucrose gradient fractions 3 and 4 (DRMs) from CTL (filled bars), MβCD (open bars) and MβCD + Chol (dashed bars). IDE and flotillin-1 were dramatically affected by membrane-lipid manipulation (n = 3; *p < 0.05 as compared to CTL values in each fraction). Fraction 2: top of the gradient. Fraction 9: bottom of the gradient.