ABSTRACT
The comparative study of the cholinesterase activity in some crab species was carried out for the first time with use of a set of thiocholine substrates. The substrate specificity was studied in stellar nerve, heart, and hemolymph of three crab species. The crab hemolymph was shown to be characterized by the highest enzyme activity. The enzyme from various crab organs has different structure o substrate specificity. Properties of crab enzymes was compared with acetylcholinesterase (AChE) of human blood erythrocytes, butyrylcholinesterase (BuChE) of horse blood serum, enzyme o squids and bivalve molluscs. The obtained data allow the conclusion to be made on differences in properties of enzymes both at the interspecies and at the tissue levels.
Subject(s)
Cholinesterases/chemistry , Crustacea/enzymology , Animals , Cattle , Hemolymph/enzymology , Horses , Kinetics , Myocardium/enzymology , Nerve Tissue/enzymology , Substrate Specificity , Thiocholine/chemistry , Tissue DistributionABSTRACT
Substrate properties of brain cholinesterases were studied in ringed seal and beluga. Kinetic parameters of hydrolysis of thiocholine esters of carboxylic acids were determined. According to the substrate specificity, the enzyme from the brain of marine mammals can be assigned to acetylcholinesterases. Specific properties of the enzyme from the brain of marine mammals were demonstrated in comparison with land animals. The revealed differences in kinetic parameters of the brain enzyme activity are considered in terms of different biochemical adaptation in ringed seal and beluga.
Subject(s)
Acetylcholinesterase/analysis , Adaptation, Physiological/physiology , Beluga Whale/physiology , Brain Chemistry/physiology , Brain/enzymology , Phoca/physiology , Acetylcholinesterase/metabolism , Animals , Kinetics , Species Specificity , Substrate SpecificityABSTRACT
An analysis of brain cholinesterase properties in 3 species of cartilaginous fishes and 1 species of chondrostei, was conducted for the first time. The skates brain enzymes, as to substrate specificity, are shown to be referred to acetylcholinesterases, and the shark brain cholinesterase - to atypical acetylcholinesterase. Kaluga brain cholinesterase, as to its substrate specificity, differes from brain enzymes of cartilaginous fishes. The differences in properties of the nervous tissue cholinestarase of the investigated fish species are the parameters of evolutionary divergence of species.
