Comparative analysis of sensitivity of proteases (chymotrypsin and trypsin) and cholinesterases of different origin to some organophosphorus inhibitors

The antichymotrypsin, antitrypsin, and anticholinesterase potencies of four homologous series of organophosphorus inhibitors are compared: O-(n-alkyl) methylthiophosphonates, O-(n-alkyl)-S-(n-butyl) methylthiophosphonates, O-(n-alkyl)-S-(β-ethylmercaptoethylene) methylth-iophosphonates, and their methylsulfomethylates. As sources of α-chymotrypsin and trypsin, commercial preparations from Worthington Biochemical Corporation and Leningrad Myasokombinat were tested. Bimolecular constant of the reaction rate was used as the measure of antienzyme potency. In all cases, the antichymotrypsin efficiency was lower, while the antitrypsin-essentially higher than the anticholinesterase activity of the studied inhibitors. These differences were found to much depend both on the inhibitor structure and on the nature of the cholinesterase preparations.     

Comparative-enzymological study of cholinesterases from optic ganglia of the Commander squid Berryteuthis magister individuals inhabiting different zones of the species areal

In this review a comparative analysis is performed of enzymological characteristics of cholinesterase (ChE) from optic ganglia of individuals of the Commander squid Berryteuthis magister caught in 8 zones of its habitation areal in the northern-western Pacific aquatorium, of ChE of the Pacific squid Todarodes pacificus as well as of the "standard" acetylcholinesterase from human erythrocytes and butyrylcholinesterase from horse blood serum. By the method of the substrate-inhibitor analysis there was shown heterogeneity of ChE preparations from the B. magister individuals from different habitation zones. Kinetic parameters of the enzymatic hydrolysis of 8 ester substrates are presented as well as the data on study of inhibitory specificity with use of 20 irreversible organophosphorus inhibitors, which show identity of ChE properties in the B. magister individuals from different habitation zones. Study of the process of the ChE reversible inhibition from the Commander squid individuals under action of 57 mono- and bisonium inhibitors has revealed differences in ChE properties of squid individuals from isolates in different zones of the habitation areal, which argues in favor of the existence of intraspecies groups of the Commander squid B. magister.     

Comparative Enzymology of Cholinesterases Underlies the Biochemical Method of Squid Taxonomy

Classification and evaluation is performed of comparative enzymologic parameters of cholinesterase activity (ChEA) in the optic ganglia tissue of individuals of different squid species with different habitats, the parameters used in the biochemical method of Cephalopoda taxonomy. Seven species of oceanic squids belonging to three families, Ommastrephidae (subfamilies Ommastrephinae and Todaradinae), Thysanoteuthidae and Gonatidae, are studied. As cholinesterase effectors, 8 substrates, 8 irreversible organophosphorus inhibitors, and 17 reversible onium inhibitors are tested. Different levels of comparison of the enzymologic parameters of ChEA are proposed. First, the enzymatic homogeneity or heterogeneity of ChEA is a criterion of interspecies difference. Second, the interspecies differences may be evaluated from parameters of the ChEA substrate specificity in different squid species. Third, use of irreversible organophosphorus inhibitors is the test that is essentially simpler, sufficiently sensitive, and reliable for comparison in the enzymologic method. Fourth, the finer nuances of the taxonomy at the level of intraspecies differences can be revealed by using reversible onium inhibitors of different structure. The enzymologic method of the squid taxonomy has allowed revealing isolation of populations of Ommastrephes bartrami individuals from different parts of the broken habitation areal.