Substrate preferences of wild and a mutant house fly acetylcholinesterase and a comparison with the bovine erythrocyte enzyme.
Comparisons were made of purified acetylcholinesterase from the heads of wild type house flies with a mutant form (which bound organophosphates and carbamates less tightly). Using 12 substrates and 6 quaternary inhibitors, the only substantial difference was that the Km for butyrylcholine was 25 times greater for the mutant enzyme, suggesting that butyrylcholine and the organophosphates and carbamates shared a common binding site. The pure enzyme from the wild type house fly was also compared with bovine erythrocyte acetylcholinesterase. The major difference was again with butyrylcholine as substrate: the ability to acylate or deacylate was 30 times greater in the fly enzyme (the Km values differed by a factor of 4).
D000110:Acetylcholinesterase / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D000818:Animals; D002417:Cattle; D004912:Erythrocytes / Q000201:enzymology; D006257:Head; D006793:Houseflies / Q000201:enzymology* / Q000235:genetics; D007700:Kinetics; D009154:Mutation; D013045:Species Specificity; D013379:Substrate Specificity
D000110:Acetylcholinesterase