| Abstract: | α-amylase of sorghum malt has been purified by a combination of charcoal and heat treatment, DEAE-cellulose and calcium phosphate chromatography, and gel filtration, yielding a product with a specific activity of 10,304 units per mg nitrogen. Both in the ultracentrifuge and on electrophoresis the purified α-amylase revealed a single peak. Results are presented for the molecular weight, sedimentation, diffusion and amino-acid composition of the purified enzyme. The influence of pH, temperature, and substrate concentration on the enzymic hydrolysis of gelatinised soluble starch has been studied. Examination of the purified α-amylase on a calcium phosphate column showed that the enzyme is micro-heterogeneous and it was separated into four sub-fractions. The physical, chemical and kinetic properties of the sub-fractions are almost identical. |
