Purification of wheat germ amylase by precipitation

alpha-Amylase from various sources was found to bind alginate in free solution. The alginate-enzyme complex could be precipitated with Ca(2+). The enzyme activity could be recovered by dissolving the precipitate in 1 M maltose and precipitating alginate alone by addition of Ca(2+). Based upon these observations, alpha-amylase from wheat germ was purified with 68-fold purification and 72% recovery. The molecular weight estimated by SDS-PAGE was 18 kDa. The method also worked equally well with alpha-amylase for the whole wheat seed. The latter enzyme could be purified 54-fold with 70% activity recovery. The molecular weight of this second enzyme was estimated to be 45 kDa by SDS-PAGE.