| Crude protein extracts from Thai rice seeds were screened for α-amylase inhibitory activity. At least 5 rice seed extracts exhibited a potent α-amylase inhibitory activity with specific activity above 50% inhibition per μg protein. Those α-amylase inhibitory activities have no positive correlation with α-amylase activity in each rice sample. Denatured SDS-PAGE revealed major proteins bands with molecular mass around <20, 28 and 40 kDa. Anion-exchange column chromatographic profile of Q-Sepharose XL at buffer system of 8.5 showed the bound proteins contained α-amylase inhibitory activity. The results indicated that proteins with molecular mass around <20 kDa, pI> 8.5 and heat stable, might be responsible for α-amylase inhibitory activity in those... |
