抄録
1. A Bacillus species, strain W-2, possesses a glucokinase as a “constitutive” enzyme, which can be extracted from cells by grinding with glass powder.
2. Cell-free preparations prepared and partially purified from the organism phosphorylate glucose with the aid of ATP, but are completely inactive towards fructose. Mannose, galactose and L-arabinose are also phosphorylated by the preparations at rates of 10, 8 and 15 per cent, respectively, of that for glucose, whereas D-glucosamine, D-ribose, D-xylose and sedoheptulose are all inactive.
3. The pH-activity curve of this enzyme has two maxima at pH 6.9 and 8.4.
4. The activity of this enzyme depends on the presence of either Mg_??_ or Mn_??_. Mg_??_is twice more effective as activator than Mn_??_ as compared at their respective optimal concentrations.
5. The enzyme is strongly inhibited by Cu_??_, Hg_??_, iodoactate and p-chloromercuribenzoate. Alloxan is also inhibitory to the enzyme. The inhibition caused by alloxan can be reversed by cysteine.
