| 摘要 |
PROBLEM TO BE SOLVED: To obtain the subject new enzyme consisting of a modified phytase derived from a bacterium belonging to the genus Aspergillus, having improved properties capable of giving myoinositol and inorganic phosphoric acid by acting on phytic acid, and useful as a food additive, a feed additive, etc. SOLUTION: This enzyme is a new modified phytase having an improved activity obtained by partially modifying the amino acid sequence of the phytase of Aspergillus fumigatus through the comparison between the structure of phytase's active sites of Aspergillus fumigatus and that of Aspergillus niger which has more preferable properties of activity. The enzyme has an effect for hydrolyzing phytic acid into myoinositol and inorganic phosphoric acid, and useful as a food additive, a feed additive, etc. The modified phytase is obtained as follows: a structure of phytase having a more preferable activity is designed using computer based on the three-dimensional structure of the phytase of Aspergillus niger to obtain a model structure; and the amino acid sequence of the phytase of Aspergillus fumigatus is partially modified according to the model structure. |
