Alpha-amylase inhibitory activity from crude protein extract of Thai rice seedsOryza sativavariety Hawm Tung and its partial protein purification

This study aimed to characterize and partial purify ?-amylase inhibitor protein of crude extract from Thai rice seeds (Oryza sativa var. Hawm Tung). The result showed that the crude extract could inhibit porcine pancreas ?-amylase activity. The inhibitor was found to be heat stable up to 85 ?C and had two pH optima of 5 and 7. The crude extract could inhibit ?-amylase activity on gel as determined by native-PAGE. In partial purification, the crude extract was salt fractionated and subsequence separated by Q-sepharose column. Both bound and unbound protein fractions from Q-sepharose column contained the inhibitory activity. SDS-PAGE revealed that all of Q-sepharose fractions contained major proteins with molecular weight around 14-16 kDa. This research revealed the potential research and development of protein from Thai rice grain (Oryza sativa var. Hawm Tung) as food supplement product for blood sugar and weight loss control.