title: A Chromogenic Assay Suitable for High-Throughput Determination of Limit Dextrinase Activity in Barley Malt Extracts.
abstract: Twenty-four malt samples were assayed for limit dextrinase activity using a chromogenic assay developed recently in our group. The assay utilizes a small soluble chromogenic substrate which is hydrolyzed selectively by limit dextrinase in a coupled assay to release the chromophore 2-chloro-4-nitrophenol. The release of the chromophore, corresponding to the activity of limit dextrinase, can be followed by measuring the UV absorption at 405 nm. The 24 malt samples represented a wide variation of limit dextrinase activities, and these activities could be clearly differentiated by the assay. The results obtained were comparable with the results obtained from a commercially available assay, Limit-Dextrizyme from Megazyme International Ireland. Furthermore, the improved assay uses a soluble substrate. That makes it well suited for high-throughput screening as it can be handled in a 96-well plate format.
authors.affiliation: Carlsberg Laboratory , Gamle Carlsberg Vej 10, 1799 Copenhagen V, Denmark.
authors.forename: Marie
authors.initials: M
authors.lastname: Bøjstrup
authors.affiliation: Carlsberg Laboratory , Gamle Carlsberg Vej 10, 1799 Copenhagen V, Denmark.
authors.forename: Lucia
authors.initials: L
authors.lastname: Marri
authors.affiliation: Carlsberg Laboratory , Gamle Carlsberg Vej 10, 1799 Copenhagen V, Denmark.
authors.forename: Finn
authors.initials: F
authors.lastname: Lok
authors.affiliation: Carlsberg Laboratory , Gamle Carlsberg Vej 10, 1799 Copenhagen V, Denmark.
authors.forename: Ole
authors.initials: O
authors.lastname: Hindsgaul
mesh_terms: D001515:Beer; D002863:Chromogenic Compounds / Q000378:metabolism*; D005285:Fermentation; D006026:Glycoside Hydrolases / Q000032:analysis / Q000378:metabolism*; D001467:Hordeum / Q000201:enzymology*; D009596:Nitrophenols / Q000032:analysis / Q000378:metabolism; D010936:Plant Extracts / Q000737:chemistry*
chemical_list: D002863:Chromogenic Compounds; D009596:Nitrophenols; D010936:Plant Extracts; D006026:Glycoside Hydrolases; C100181:pullulanase; C548837:2-chloro-4-nitrophenol
keywords: brewing; chromogenic substrate; enzyme assay; limit dextrinase; malt