Analysis Note

Protein determined by biuret

Application

Butyrylcholinesterase (BChE) from equine serum has been used:to determine the inhibitory concentration of bupivacaine on butyrylcholinesterasein acetylcholinesterase (AChE)/BChE activity assay to determine the inhibitory activity of benzothiazole-piperazine compounds

Selective inhibition of BChE activity can be used in the detection of organophosphates. Its use in the treatment of organophosphate toxicity shows promise. There is a correlation between the level of BChE in human blood and degree of protection against potentially toxic nerve agents. There has also been interest in the roles of cholinesterases with regard to Alzheimer’;s disease. Investigations into selective inhibitors may provide a clearer picture of the physiological role of BChE in both healthy and diseased individuals. The enzyme has been used to test bupivacaine as an inhibitor of butyrylcholinesterase during acetylcholinesterase assay using cerebrospinal fluid.

Biochem/physiol Actions

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⁺ and the activity is constant over the pH range 6.0-8.0. It is inhibited by Betaine, nicotine, organophosphates, carbamates.

Packaging

1000 units in poly bottle

Physical form

Highly purified, lyophilized powder containing buffer salts

Unit Definition

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.