Denaturation of Bacillus amyloliquefaciens alpha-amylase with urea.

The urea induced denaturation of the Bacillus amyoliqefaciens alpha-amylase (E.C. 3.2.1.1) was studied by absorption measurements in the near ultra-violet region and specific activity measurements. Spectral measurements were made at pH 6.9 and over the temperature range 20-80 degrees C. It has been observed that urea induced a cooperative transition. In the absence of denaturant, the Gibs energy changes were in the range of 8-15 kcal mol(-1). alpha-amylase lost 80% of its activity in the concentrated solution of urea. alpha-amylase was more thermostable than other mesophilic enzymes.