RESUMEN
The comparative study of irreversible inhibitory action of some substituted vinyl-phosphates (in usual and betaine forms on cholinesterases from different biological sources such as the human blood erythrocytes, the horse and the hen blood serum and optic ganglia of the squid) has been carried out. It is shown that betaines obtain lesser inhibitory activity as compared with the corresponding ordinary vinylphosphates. Some of tested inhibitors display expressed selectivity of action. So, the compound GL-2 reacts with cholinesterase of optic ganglia of the squid 450 000 times faster than with cholinesterase of the hen blood serum. The application of vinylphosphates as inhibitors of cholinesterases allows displaying additional differences in properties of enzymes. It is very important for comparative enzymology. These compounds may be used for detalization of type belonging and to make the classification of cholinesterases more accurate. Moreover, the estimation of anticholinesterase activity of vinylphosphates is important because these compounds may be used both in medicine and agriculture.
Asunto(s)
Betaína/farmacología , Inhibidores de la Colinesterasa/farmacología , Eritrocitos/efectos de los fármacos , Compuestos Organofosforados/farmacología , Compuestos de Vinilo/farmacología , Acetilcolinesterasa/sangre , Animales , Butirilcolinesterasa/sangre , Eritrocitos/enzimología , Caballos , HumanosRESUMEN
The action of some phosphonium betains on cholinesterases from different biological sources has been studied. It has been shown, that all studied betains are reversible inhibitors of cholinesterase hydrolysis of acetyltiocholine. Inhibiting action of these compounds on acetylcholinesterases is about ten times weaker that of the majority of known phosphonium salts, while their action on butyrylcholinesterases has no peculiarities. There were found certain differences for each betain compounds in their action on cholinesterases from different biological sources. These results may be used for detail classification of cholinesterases and allow to extend knowledge in comparative enzymology.
Asunto(s)
Betaína/análogos & derivados , Inhibidores de la Colinesterasa/farmacología , Colinesterasas/efectos de los fármacos , Animales , Catálisis/efectos de los fármacos , Bovinos , Pollos , Columbidae , Eritrocitos/efectos de los fármacos , Eritrocitos/enzimología , Peces , Caballos , Humanos , Masculino , Espectrofotometría , Factores de TiempoRESUMEN
A kinetic investigation of the human erythrocyte and housefly head acetylcholinesterase irreversible inhibition with thiovinyl phosphates is performed and an activation effect of thioalkyl alpha-substituents in the vinyl group is observed. Thiovinyl phosphates in vitro are less selective to the insect enzyme than the corresponding oxygen analogues. Their inhibitory potency rises with lengthening of the alkoxyl radicals at a phosphorus atom but the correlation with the toxicity is absent. Phosphonium salts having a thiovinyl substituent inhibit the enzyme via the reversible mechanism typical for onium compounds.