Purification and characterization of α-amylase from safflower (Carthamus tinctorius L.) germinating seeds

α-Amylase (α-1-4 D-glucan glucanohydrolase EC 3.2.1.1) crude extract was obtained from safflower (Carthamus tinctorius L.) cotyledons excised from 5-day-old dark grown seedlings. The enzyme was purified by precipitating the crude extract with ammonium sulphate at 20–60% saturation, and then by subjecting this fraction to affinity chromatography on a β-cyclodextrin-Sepharose 6B column. The active fraction was dialysed and concentrated. An overall purification of about 131 folds with an activity yield of 81.25% was achieved. The molecular mass of purified enzyme determined by SDS-PAGE was 35 kD. When the purified α-amylase was subjected to gel electrophoresis followed by negative staining, only one band of active protein was detected. Its maximal activity was in the pH 6.0 and at a temperature of 55 °C. This enzyme was activated by Ca2+ and inhibited by Fe2+. To cite this article: M. Ben Elarbi et al., C. R. Biologies 332 (2009).