[Isolation and study of physico-chemical properties of alpha-amylase from Bacillus subtilis]

By chromatography on ultragel ACA-54 alpha-amylase was isolated from the enzymic preparation amylosubtilin G10x. As compared to the initial preparation, the specific activity of the purified enzyme per mg increased 25-fold. The major physico-chemical characteristics of alpha-amylase were determined. The molecular weight of the enzyme measured by gel-chromatography and electrophoresis was estimated to be 49,000. The isoelectric point determined by electrofocusing was found to be 5,2. Irreversible acid inactivation of the enzyme in the range of pH 2-5 was investigated. The reaction was found to develop in at least two stages.