title: Microassay for rapid screening of alpha-amylase activity.
abstract: A microassay was developed for measuring the activity of alpha-amylases in the nanogram enzyme concentration range, based on the use of dye-labeled cross-linked starch as the substrate, and the release of soluble colored fragments formed in enzyme hydrolysis. Reaction conditions were optimized to generate a linear correlation between the increase in absorbance and a reaction time of 0-10 min, as well as enzyme concentrations in the range of 0-50 ng. A standard curve for the conversion of absorbance to enzyme activity units was constructed. The protocol developed was applied to monitoring the production of ultralow concentrations of recombinant barley alpha-amylase in yeast cells.
authors.affiliation: Western Regional Research Center, Agricultural Research Service, U.S. Department of Agriculture, 800 Buchanan Street, Albany, California 94710, USA. dwsw@pw.usda.gov
authors.forename: D W
authors.initials: DW
authors.lastname: Wong
authors.forename: S B
authors.initials: SB
authors.lastname: Batt
authors.forename: G H
authors.initials: GH
authors.lastname: Robertson
mesh_terms: D004396:Coloring Agents; D007527:Isoenzymes / Q000737:chemistry; D008832:Microchemistry; D011994:Recombinant Proteins / Q000737:chemistry; D013213:Starch; D000516:alpha-Amylases / Q000737:chemistry*
chemical_list: D004396:Coloring Agents; D007527:Isoenzymes; D011994:Recombinant Proteins; D013213:Starch; D000516:alpha-Amylases