THE HORSE SERUM BUTYRYLCHOLINESTERASE ACTIVITY UNDER OCTANOL INFLUENCE

Butyrylcholinesterase preparations from horse blood serum widely use in the research purposes and as an analytical reagent for determination of biologically active substances. High sensitivity of butyrylcholinesterase to organophosphorous inhibitors which possess high toxicity for the warm-blooded is especially important. Influence of octanol on reactive capacity of horse serum butyrylcholinesterase to butyrylcholine and α-naphtylacetate and on its sensitivity to diisopropylfluorophosphate is investigated. Enzyme activity measured by a method of potentiometric titration in experiments with butyrylcholine and a fluorimetric method in experiments with α-naphtylacetate allowing to define speed of hydrolysis of small concentration of a substrate. It is shown, that octanol does not influence on the hydrolysis rate of butyrylcholine but activates the enzymatic hydrolysis of α-naphtylacetate and reduces the sensitivity of enzyme to inhibition by diisopropylfluorophosphate. The received results have the important practical value as octanol apply in some manufactures in the capacity of a defoamer. Our researches have shown that such standard procedures which used by manufacture of enzyme preparations as salting-out and desalting only partially delete octanol impurities. Complete separation of the enzyme from octanol and its sensitivity reduction to diisopropylfluorophosphate was possible by selective sorption of enzyme protein on the ion-exchange resin with the after-elution by a salt solution.