CLASSIFICATION OF ALPHA-AMYLASES BY ACTION PATTERNS ON MALTOOLIGOSACCHARIDES

The action patterns of various α-amylases were investigated by “the oligosaccharides mapping method.” The maltooligosaccharides labeled with 14C at 1–C of glucose moiety of the reducing ends were used as the substrates. The experimental results indicated that site of substrates to be attacked by the enzymes are at certain glucosyl linkages from the nonreducing end. Based on the chain length of saccharides with nonreducing ends formed afresh by the first attack, α-amylases were found to be divided into two groups: A) Bacillus subtilis liquefying α-, Bacillus stearothermophilus α- and malt α-amylases which hydrolyze by maltohexaosyi or maltopentaosyl units, b) Bacillus subtilis saccharifying α-, Endomycopsis α- several fungal α- and animal α-amylases which attack by maltotriosyl units. © 1969 Taylor and Francis Group LLC.