from Bacillus stearothermophilus
|Specific activity||:||more than 400 U/mg protein|
|Contaminants||:||(as PGI activity = 100%)|
|Molecular weight||:||ca. 200,000|
|Subunit molecular weight||:||ca. 54,000|
|Optimum pH||:||9.0 - 10.0||(Fig.1)|
|pH stability||:||6.0 - 10.5||(Fig.2)|
|Thermal stability||:||No detectable decrease in activity up to 60°C.||(Fig.3, 4)|
|Michaelis constants||:||(95mM Tris-HCl buffer, pH 9.0, at 30°C)|
stable at -20°C for at least one year
The change in absorbance is measured at 340nm according to the following reactions.
One unit of activity is defined as the amount of PGI that forms 1 µmol of glucose 6-phosphate per minute at 30°C.
Preparation of Enzyme Solution
Dissolve the lyophilized enzyme with distilled water and dilute to 5 to 10 U/mL with 50mM Tris-HCl buffer, pH 8.5.
|Solution I||28.44mL||Solution III||0.60mL|
|Solution II||0.90mL||Solution IV||0.06mL|