title: Bi-fluorescence-labeled maltoheptaoside: convenient substrate for continual assay of alpha-amylase.
abstract: A new maltoheptaose derivative was prepared as a useful substrate for continual assay of alpha-amylase. The maltoheptaoside has thionaphtyl group as a fluorescent energy donor at the reducing end and dansyl group as an acceptor group at the non-reducing end. Excitation of the thionaphthyl group at 290 nm results in emission at 523 nm from the dansyl group, while the emission from the thionaphthyl group is quenched by the dansyl group. This fluorescence energy transfer is reduced by the hydrolytic action with alpha-amylase and a significant decrease in the dansyl emission concomitant with an increase in the thionaphthyl emission was observed. Usefulness of this substrate was demonstrated for sensitive and continuous assay of alpha-amylase from Aspergillus oryzae.
authors.affiliation: Division of Biological Sciences, Graduate School of Science, Hokkaido University, Sapporo, Japan. shin@glyco.sci.hokudai.ac.jp
authors.forename: S I
authors.initials: SI
authors.lastname: Nishimura
authors.forename: N
authors.initials: N
authors.lastname: Kimura
authors.forename: K
authors.initials: K
authors.lastname: Matsuoka
authors.forename: Y C
authors.initials: YC
authors.lastname: Lee
mesh_terms: D001236:Aspergillus oryzae / Q000201:enzymology; D002240:Carbohydrate Sequence; D003505:Cyclodextrins / Q000737:chemistry; D003619:Dansyl Compounds / Q000138:chemical synthesis / Q000737:chemistry; D005456:Fluorescent Dyes / Q000138:chemical synthesis / Q000737:chemistry; D005936:Glucans / Q000138:chemical synthesis / Q000737:chemistry; D007700:Kinetics; D008969:Molecular Sequence Data; D015394:Molecular Structure; D013050:Spectrometry, Fluorescence; D013379:Substrate Specificity; D000516:alpha-Amylases / Q000032:analysis*; D047392:beta-Cyclodextrins
chemical_list: D003505:Cyclodextrins; D003619:Dansyl Compounds; D005456:Fluorescent Dyes; D005936:Glucans; D047392:beta-Cyclodextrins; C031146:maltoheptaose; D000516:alpha-Amylases; C031215:betadex