from Bacillus stearothermophilus
|Specific activity||:||more than 950 U/mg protein|
|Contaminants||:||(as AlaR activity = 100%)|
|Molecular weight||:||ca. 78,000|
|Subunit molecular weight||:||ca. 39,000|
|Optimum pH||:||10.5 - 12.0||(Fig.1)|
|pH stability||:||5.5 - 11.0||(Fig.2)|
|Thermal stability||:||No detectable decrease in activity
up to 70°C.
|Michaelis constants||:||(100mM Carbonate buffer,
pH 10.5, at 30°C)
stable at -20°C at least one year
The change in absorbance is measured at 340 nm according to the following reactions.
One unit of activity is defined as the amount of AlaR that forms 1μmol of L-alanine 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 potassium phosphate buffer, pH 7.5.
|Solution I||16.50mL||Solution IV||1.50mL|
|Solution II||3.00mL||H2O||8.25 mL|
|Solution III||0.75 mL|