[Properties of glucose isomerase from Streptomyces robeus S-606].
Optimal conditions of the glucose isomerase fixation in a cell are determined by thermal treatment of Str. robeus S-606 biomass. Under these conditions the maximal enzyme activation (by 50-55 percent) is simultaneously observed. Basic properties of glucose isomerase fixed inside the cell are studied in comparison with the enzymic cell-free extract of this enzyme. The pH-optimum for preparations coincides and is observed at pH 7.5; the temperature optimum for the soluble enzyme is 70 degrees C, and for the intracellular enzyme it is higher by 5 degrees C. Thermostability of the intracellular enzyme is also higher than that of the soluble one. The Michaelis constants are calculated for the glucose isomerase preparations in a form of producer cells and enzymic extract: they equal to 0.375 M and 0.285 M, respectively. A comparison of properties permits considering intracellular glucose isomerase as an immobilized enzymic preparation.
D019747:Aldose-Ketose Isomerases; D002238:Carbohydrate Epimerases / Q000378:metabolism*; D004789:Enzyme Activation; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D013302:Streptomyces / Q000201:enzymology*
D002238:Carbohydrate Epimerases; D019747:Aldose-Ketose Isomerases; C023298:xylose isomerase
Svoĭstva gliukozoizomerazy Streptomyces robeus S-606.