ABSTRACT
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.
Subject(s)
Enzymes/chemistry , Gelatin/chemistry , Starch/chemistry , Butyrylcholinesterase/chemistry , Butyrylcholinesterase/metabolism , Enzyme Stability , Enzymes/metabolism , FMN Reductase/chemistry , FMN Reductase/metabolism , Gels/chemistry , Kinetics , Luciferases/chemistry , Luciferases/metabolism , NAD/chemistry , NAD/metabolismABSTRACT
The functioning of NAD(P)H:FMNoxidoreductase (Red) from Vibrio fischeri under conditions of macromolecular crowding (MMC) simulated in vitro by adding biopolymers (starch and gelatin) was studied. The dissociation rate constants and the activation energies of dissociation of Red to the subunits were calculated, and the process of denaturation of Red was analyzed. It is shown that the functioning of Red both under conditions of MMC and in diluted solutions is the same. This result refutes the common belief that the native conformation of enzymes in vivo is stabilized due to MMC as compared to the in vitro conditions.
