[Inhibition of glucose isomerase from Actinomyces olivocinereus 154 by polyols].

The inhibitory action of polyols, e. g. D-mannitol, D-glucitol, ribitol and xylitol, on the activity of glucose isomerase prepared from Actinomyces olivocinereus 154 was studied. All the polyols under study are purely reversible competitive inhibitors. The values of Ki for D-mannitol, D-sorbitol, D-arabitol, D-glucitol, ribitol and xylitol are 0.200, 0.140, 0.030, 0.024 and 0.020 M, respectively. The inhibition is to some extent decreased by increasing concentrations of the substrate and is completely abolished by increasing concentrations of Mg2+ and Co2+--up to 5.10(-2) and 5.10(-3) M, respectively.