title: Bacillus stearothermophilus neopullulanase selective hydrolysis of amylose to maltose in the presence of amylopectin.
abstract: The specificity of Bacillus stearothermophilus TRS40 neopullulanase toward amylose and amylopectin was analyzed. Although this neopullulanase completely hydrolyzed amylose to produce maltose as the main product, it scarcely hydrolyzed amylopectin. The molecular mass of amylopectin was decreased by only one order of magnitude, from approximately 10(8) to 10(7) Da. Furthermore, this neopullulanase selectively hydrolyzed amylose when starch was used as a substrate. This phenomenon, efficient hydrolysis of amylose but not amylopectin, was also observed with cyclomaltodextrinase from alkaliphilic Bacillus sp. strain A2-5a and maltogenic amylase from Bacillus licheniformis ATCC 27811. These three enzymes hydrolyzed cyclomaltodextrins and amylose much faster than pullulan. Other amylolytic enzymes, such as bacterial saccharifying alpha-amylase, bacterial liquefying alpha-amylase, beta-amylase, and neopullulanase from Bacillus megaterium, did not exhibit this distinct substrate specificity at all, i.e., the preference of amylose to amylopectin.
authors.affiliation: Biochemical Research Laboratory, Ezaki Glico Co., Ltd., Nishiyodogawa-ku, Osaka 555-8502, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Kamasaka
authors.forename: Kazuhisa
authors.initials: K
authors.lastname: Sugimoto
authors.forename: Hiroki
authors.initials: H
authors.lastname: Takata
authors.forename: Takahisa
authors.initials: T
authors.lastname: Nishimura
authors.forename: Takashi
authors.initials: T
authors.lastname: Kuriki
mesh_terms: D000687:Amylopectin / Q000378:metabolism*; D000688:Amylose / Q000378:metabolism*; D001407:Bacillus; D001411:Geobacillus stearothermophilus / Q000201:enzymology*; D006026:Glycoside Hydrolases / Q000378:metabolism*; D006868:Hydrolysis; D008320:Maltose / Q000378:metabolism*; D013379:Substrate Specificity
chemical_list: D008320:Maltose; D000688:Amylose; D000687:Amylopectin; D006026:Glycoside Hydrolases; C058484:neopullulanase