FIGURE 3.
Formation of AChE-BChE G4 hybrid tetramer in the presence of PRiMA II and QN-GPI. HEK293T cells were transfected with cDNAs encoding AChET and/or BChET with PRiMA (A) or QN-GPI (D) (14) for 2 days. Sucrose density gradient analysis was performed as in Fig. 1A. B and E, G4-enriched fractions shaded in A and D were collected for immunoprecipitation by either anti-AChE or anti-BChE antibody as in Fig. 1B. The co-immunoprecipitation of AChE and BChE indicates the existence of G4 hybrid tetramers. The enzymatic activities are expressed in arbitrary units. The values are the means ± S.E. (n = 3), each with triplicate samples. C and F, G4-enriched fractions shaded in A and D were analyzed by nondenaturing electrophoresis. The enzymatic activities of AChE and BChE were visualized by Karnovsky staining. A new oligomer migrating between G4 AChE and G4 BChE was found in the triple transfection, suggesting that PRiMA II and QN-GPI, like PRiMA I, induce the formation of the AChE-BChE hybrid tetramer. Ab, antibody; IP, immunoprecipitation.