Kuznetsova_1995_Ukr.Biokhim.Zh.(1978)_67_49

Catalytic properties of human blood erythrocyte acetylcholinesterase, horse blood serum butyrylcholinesterase and squid visual cholinesterase nonimmobilized and immobilized in N-phthalylchitozane and in gelatin have been comparatively studied. Immobilization of cholinesterases in N-phthalylchitozane does not change its catalytic properties in respect to substrates and inhibitors but increases the enzyme stability. Cholinesterase immobilization in the gelatin membrane increases the Michaelis constants and decreases the maximum velocities in the reaction of enzyme hydrolysis of thiocholine esters and (for squid visual ganglia cholinesterase) of indophenylacetate. The effect of irreversible inhibitor diisopropylfluorophosphate and reversible inhibitors N-methyl-4-piperidinyl benzylate and tacrine on cholinesterases immobilized in the gelatin is weaker as compared with the effect on nonimmobilized enzymes. The results obtained are discussed for the effect of immobilization on the active enzyme surface.