Figure 4. Distribution of gangliosides radioactivity and proteins in the different fractions of the sucrose gradient.

CGCs, after incubation with different gangliosides (GM3, GM1 or GD1a) and correspondent radiolabelled gangliosides ([³H]GM3, [³H]GM1 or [³H]GD1a), at a final concentration of 2×10⁻⁶ M at 37°C for 4 h, were treated with 1% Triton X-100-containing buffer for 30 min on ice. The cellular lysate was submitted to discontinuous sucrose density gradient centrifugation. One-milliliter fractions were withdrawn from the gradient and submitted to [³H]GM3, [³H]GM1 or [³H]GD1a radioactivity determination (panel A) and evaluation of proteins distribution (panel B). Data are means ± SD from at least three independent experiments performed in triplicate.