Quaternary Structure and Hydrophobic Interactions of Drosophila Acetylcholinesterase in Wild Type Flies and in Mutants of the Ace Locus

Abstract

Adult Drosophila acetylcholinesterase (AChE) is predominantly a disulfide-linked dimer of globular subunits (Toutant et al., 1988). Each catalytic subunit possesses a C-terminal phosphatidylinositol that anchors the molecule to the membrane (Gnagey et al., 1987; Fournier et al., 1988a). Phosphatidylinositol-specific phospholipase C (PI-PLC) releases the terminal glycolipid and converts the membrane-bound AChE to a hydrophilic form which no longer interacts with nondenaturing detergents. Thus, the original dimer is referred to as an amphiphilic molecule. We present here additional structural data on the dimeric AChE of adult wild type Drosophila. We also report preliminary results on the structure of AChE in certain mutants of the Ace locus (Hall et al., 1980; Greenspan et al., 1980).