[How the various substrates activate the process of enzymatic hydrolysis by different cholinesterases].
Kinetic analysis of the activating effect of substrate on the cholinesterase catalysis is performed. There are determined values of coefficient of activation A in the pH zone 5.0-7.5 for the process of hydrolysis of acetylcholine, indophenylacetate (IPA), and 2,6-dichlorophenolindophenylacetate (DIPA) by cholinesterase (ChE) of horse blood serum, as well as of IPA and DIPA by ChE of optical ganglia of the Pacific squid Todarodes pacificus. The phenomenon of activation has not been revealed at hydrolysis of phenylacetate by the horse blood serum ChE. The conclusion is made that the cause of the activating effect of substrate on the process of enzymatic hydrolysis by ChEs of different origin is the presence of the onium grouping in the structure of substrates.
N E
NE
Basova
E V
EV
Rozengrart
D000109:Acetylcholine / Q000737:chemistry*; D000818:Animals; D002802:Cholinesterases / Q000737:chemistry*; D049832:Decapodiformes; D004789:Enzyme Activation; D006736:Horses; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007215:Indophenol / Q000031:analogs & derivatives* / Q000737:chemistry; D000644:Quaternary Ammonium Compounds / Q000737:chemistry*; D013379:Substrate Specificity
D000644:Quaternary Ammonium Compounds; D007215:Indophenol; C001002:diisopropylamine dichloroacetate; C016519:indophenyl acetate; D002802:Cholinesterases; D000109:Acetylcholine