FIGURE 5.

Oligomerization of human AChE, BChE, and mutants lacking the C-terminal t-peptide or containing exchanged t-peptides. A, comparison of the amino acid sequences of C-terminal t-peptides from human AChE and BChE. Identical residues are indicated by asterisks. Highly and moderately similar residues are indicated by double dots and single dots, respectively. B, schematic representations of AChE_T, BChE_T, and their mutants. AChE_T and BChE_T are wild-type human AChE and BChE, respectively. AChE_ΔT and BChE_ΔT are mutants in which the t-peptides were deleted. AChE_BChE-T and BChE_AChE-T are chimeras in which the t-peptides of AChE and BChE were exchanged. C, HEK293T cells were transfected with cDNAs encoding AChE_T, AChE_ΔT, AChE_BChE-T, BChE_T, BChE_ΔT, or BChE_AChE-T with and without cDNA encoding PRiMA for 2 days. Cell extracts containing equal amounts of enzymatic activity were subjected to sucrose density gradient analysis as in Fig. 1A. The positions of the peaks corresponding to the G₁, G₂, and G₄^a forms of AChE (left panel) and BChE (right panel) are shown by vertical dashed lines. Enzymatic activities are expressed in arbitrary units, and one representative result is shown (n = 4).