MODIFIED CYCLODEXTRIN-SYNTHESIZING ENZYME AND ITS PRODUCTION AND PRODUCTION OF CYCLODEXTRIN WITH THE ENZYME

摘要

PROBLEM TO BE SOLVED: To obtain a new modified synthetic enzyme in which tyrosine constituting the active center of the region A of a cyclodextrin-synthesizing enzyme is replaced with another amino acid, and which gives the reaction product greatly high in the amount of the synthesized α-cyclodextrin. ;SOLUTION: This new modified cyclodextrin-synthesizing enzyme wherein the 100-tyrosine constituting the active center of the region A of a cyclodextrin- synthesizing enzyme having an amino acid sequence of the formula is replaced with another amino acid such as tryptophane, phenylalanine, leucine or aspartic acid. The action of the enzyme on a substrate such as starch can give the reaction product greatly high in the content of the α-cyclodextrin. The modified enzyme is obtained by extracting the chromosome from Bacillus macerans IAM 1243, multiplying the chromosome with PCR using a synthesized primer containing the base sequence of the cyclodextrin-synthesizing enzyme, subjecting the multiplied chromosome to a site-specific mutation so as to replace the tyrosine of the active center of the obtained gene with another amino acid.;COPYRIGHT: (C)1997,JPO