title: [An improved method of photometric determination of cyclodextrin glucanotransferase activity].
abstract: The method of spectrophotometric determination of cyclodextrin glucanotransferase (CGTase, EC 2.4.1.19) activity with the use of phenolphthalein as a colored reagent has been improved. This technique includes an enzymatic reaction at 40 degrees C for 60 min in 2% starch, with subsequent supplementation of the reaction mixture (0.5 ml) with the phenolphthalein reagent (3.0 ml) prepared in 0.1 M potassium carbonate buffer (pH 11.0) according to a special procedure, and measurement of the optical density of the obtained mixture at 553 nm. The activity was calculated using the exponential growth equation that connects a drop in the optical density and the degree of dilution of the enzyme. The described technique is suitable for working in a sufficiently broad range of specific activity of beta-CGTase and does not require precise adjustment of the degree of dilution of solutions analyzed.
authors.forename: N G
authors.initials: NG
authors.lastname: Usanov
authors.forename: E A
authors.initials: EA
authors.lastname: Gil'vanova
authors.forename: P A
authors.initials: PA
authors.lastname: Elizar'ev
authors.forename: E A
authors.initials: EA
authors.lastname: Prutsakova
authors.forename: A I
authors.initials: AI
authors.lastname: Melent'ev
mesh_terms: D002021:Buffers; D005964:Glucosyltransferases / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007202:Indicators and Reagents; D020113:Phenolphthalein; D010783:Photometry; D013696:Temperature
chemical_list: D002021:Buffers; D007202:Indicators and Reagents; D020113:Phenolphthalein; D005964:Glucosyltransferases; C019963:cyclomaltodextrin glucanotransferase