Gelatin and Starch: What Better Stabilizes the Enzyme Activity?

The regularities of the functioning of a number of enzymes in a viscous environment created by natural polymers, starch and gelatin are examined. Based on the analysis of kinetic curves of thermal inactivation, mechanisms of thermal inactivation of enzymes in a viscous microenvironment are proposed. Using the example of butyrylcholinesterase, NAD(P)H:FMN oxidoreductase, and coupled system of the luminous bacteria (NAD(P)H:FMN oxidoreductase + luciferase), the conditions, under which starch and gelatin have a stabilizing effect on enzyme activity during storage and exposure to various physical and chemical environmental factors, were found. A significant increase in the stabilizing effect is achieved by eliminating water during drying the enzyme preparations immobilized in starch and gelatin polymer gels.

Types of Pesticides Interaction in Mixtures: Results of Inhibitory Assay

Enzymatic inhibitory assay based on the coupled enzyme system NAD(P)·H:FMN oxidoreductase and luciferase (Red + Luc), originally developed for environmental monitoring of soils, water, and air, is proposed as a method for evaluating changes in the properties of active ingredients of pesticide preparations depending on the additional components (formulants), as well as when pesticides are combined in mixtures. Using the commercial pesticide preparations containing glyphosate, it was shown that the degree of inhibition of the coupled enzyme system Red + Luc largely depends on the formulants rather than on the active ingredient in their composition. Moreover, the combined inhibitory effect of the pesticides mixture on the coupled enzyme system Red + Luc was not additive. According to the results of the inhibitory assay, the type of interaction of pesticide preparations in mixtures depends on both the formulants used and the ratio of pesticides in the mixture.