A Comparison of the Cholinesterase in the Heads of the House Fly, the Cockroach, and the Honey Bee

Abstract

The enzymatic activity of the cholinesterase in the heads of the house fly, Musca domestica L., honey bee, Apis mellifera L., and cockroach, Periplaneta americana (L.), were compared using acetylcholine bromide, acetyl-beta-methyl choline chloride, and triacetin as substrates. In each case, the enzymatic activity was inhibited by excess acetylcholine bromide but not by excess acetyl-beta-methylcholine chloride or triacetin. In the house fly, one enzyme apparently splits the acetylcholine and the methyl derivative. In the honey Bee, two enzymes were apparently present. The importance of using several substrate concns. when attempting to classify cholinesterase activity is emphasized.