Butyrylcholinesterase from equine serum

Selective inhibition of BChE activity can be used in the detection of organophosphates. Its use in the treatment of organophosphate toxicity has been explored. It has been reported that the level of BChE in human blood correlates to the degree of protection against potentially toxic nerve agents. Cholinesterases have also been investigated for their role in Alzheimer′s disease.

Butyrylcholinesterase (BChE) is a serine hydrolase that is structurally similar to acetylcholinesterase (AChE), but differs in substrate specificities and inhibitor sensitivities.BChE can, unlike AChE, efficiently hydrolyze larger esters of choline such as butyrylcholine and benzoylcholine. The enzyme is a tetrameric glycoprotein with four equal subunits (110 kDa each). The enzyme is activated by Ca²⁺ and Mg²⁺. The activity is constant over the pH range of 6.0-8.0. It is inhibited by betaine, nicotine, organophosphates, and carbamate.

Highly purified; contains buffer salts

Protein determined by biuret

One unit will hydrolyze 1.0 μmole of butyrylcholine to choline and butyrate per min at pH 8.0 at 37 °C. The activity obtained using butyrylcholine as substrate is ~2.5 times that obtained using acetylcholine.