Sulfuric Acid → D-(-)-Fructose

Participants

Reaction Steps

The glucose isomerase activity in the particles was determined by placing a 0.1 gram of the enzyme in a 250 ml erlenmeyer flask and adding 50 ml of substrate [2M glucose, 20 mM MgSO4.7H2O, 0.5 mM CoCl2.6H2O and 20 mM HEPES (N-2-hydroxyethylpiperazine-N'-2-ethanosulfonic acid) buffer adjusted to pH 8.0]. The dried particles were allowed to hydrate for about one hour at room temperature. At zero time, the flask was placed in a 60° C. water bath. The flask was agitated by a shaker water bath at a rate that provided particle movement. At 10 minutes and at 70 minutes, a 0.1 ml sample was removed from the assay mixture and added to 4.0 ml of 0.1M HClO4. The amount of fructose formed was determined by the cysteine-H2SO4 method (Dische, Z. J. Biological Chemistry, Vol. 181, p. 379, 1949) by incubating 0.05 ml of sample with 0.5 ml of 5% cysteine and 4.5 ml of 75% H2SO4 at 37° C. for 30 minutes and reading the absorbance at 412 nm. A unit of immobilized glucose isomerase activity (IGIU) is that amount of enzyme that produces one micromole of fructose per minute.

Provenance & Evidence