[The effect of pH and reversible inhibitors on decarbamylation of acetylcholinesterase].
Decarbamylation rate of membrane-bound methyl- and dimethyl-carbamylated acetylcholinesterase of human erythrocytes and bovine brain is reliably 1.1-1.6 times lower than that of the soluble enzyme. Such reversible inhibitors as tacrine (of non-competition action), ambenonium (mixed action) and galanthamine (competitive type of action) decelerate the decarbamylation rate of acetylcholinesterase. At pH 6 tacrine inhibits the reduction rate of soluble acetylcholinesterase activity of human erythrocytes more intensively than that of membrane-bound acetylcholinesterase. No differences in decarbamylation rate were found for the both forms of the enzyme at pH 8. Tacrine, a non-competitive inhibitor in concentrations below the inhibition constant (Ki = 1.4 x 10(-7) M) exerts the most intensive effect on the decarbamylation rate of methyl- and dimethylcarbamylated acetylcholinesterase of the mouse brain, while ambenonium and galanthamine in concentrations much (tens times) exceeding their Ki (3.1 x 10(-10) M and 4.4 x 10(-7) M, respectively) provide a decrease of the decarbamylation rate.
L I
LI
Kugusheva
V I
VI
Rozengart
O E
OE
Sherstobitov
D000109:Acetylcholine / Q000378:metabolism; D000110:Acetylcholinesterase / Q000378:metabolism*; D000549:Ambenonium Chloride / Q000494:pharmacology; D000818:Animals; D001921:Brain / Q000201:enzymology; D002417:Cattle; D002800:Cholinesterase Inhibitors / Q000378:metabolism; D004910:Erythrocyte Membrane / Q000201:enzymology; D005702:Galantamine / Q000494:pharmacology; D006801:Humans; D006863:Hydrogen-Ion Concentration; D010084:Oxidation-Reduction; D013379:Substrate Specificity; D013619:Tacrine / Q000494:pharmacology; D013696:Temperature
D002800:Cholinesterase Inhibitors; D005702:Galantamine; D013619:Tacrine; D000549:Ambenonium Chloride; D000110:Acetylcholinesterase; D000109:Acetylcholine
Vliianie pH i obratimykh ingibitorov na dekarbamilirovanie atsetilkholinésterazy.