FIGURE 6.
Comparison between the detergent resistance of PRiMA-linked and GPI-anchored AChE in membrane rafts. A, AChET may be associated as tetramers with the transmembrane protein PRiMA or with the chimeric GPI-anchored protein QN-HC, the AChEH variant forms GPI-anchored dimers. Sedimentation profiles of AChE activity obtained from transfected NG108-15 cells expressing the different proteins, as indicated. Sedimentation was performed as in Fig. 1A. B, proportions of AChE activities from total membrane preparations recovered in raft fractions obtained from the cells in A after flotation in discontinuous sucrose gradients (data not shown) in the presence of 0.02% (low) or 0.2% (high) cold Triton X-100 are shown. The values, expressed as % of the membrane-bound G2 or G4 AChE activity input in the discontinuous gradient, are means ± S.E. (n = 4). The total G4 AChE activity was calculated from the total activity input in the gradient and the proportion of G4 AChE from (A). **, p < 0.01.