SOURCE. Porcine pancreas.
SPECIFICATIONS. 3X crystallized, suspension in 0.5 saturated NaCl pH 7.0 containing 3 mM CaCl2 and 0.01% NaN3 as preservative.
MW = 52,000
Store at 5°C. Stable 9-12 months at 5°C. DO NOT FREEZE.
1500-1800 units per mg of protein. One unit will liberate 1µM of reducing groups equivalent to maltose per minute at pH 6.9 and 25°C.
Substrate is soluble starch.
Contains less than 0.01% of trypsin activity on the substrate BAPNA.
PREPARATION. Alpha-amylase is three times crystallized by our modifications of the method of Levitzki et al. (29). In the method, the alpha-amylase of porcine pancreas is preferentially absorbed to glycogen and separated as a precipitate from the non-specific protein. After digestion of the precipitate, impurities are removed by chromatography and the alpha-amylase crystallized.
Trace proteases are removed by affinity chromatography.