title: Flow-injection assay of catalase activity.
abstract: A novel flow-injection assay (FIA) system with a double line for catalase activity was constructed in which an oxidase is immobilized and the substrate is continuously pumped to reduce the dissolved oxygen and to generate a given level of hydrogen peroxide. The catalase in a sample decomposed the hydrogen peroxide, and thus the increase in dissolved oxygen dependent on the activity was amperometrically monitored using a Clark-type oxygen electrode. Among the examined several oxidases, uricase was most suitable for the continuous formation of hydrogen peroxide from a consideration of the stability and the conversion efficiency. Under the optimum conditions, a linear calibration curve was obtained in the range from 21 to 210 units/mg and the reproducibility (CV) was better than 2% by 35 successive determinations of 210 units/ml catalase preparation. The sampling frequency was about 15 samples/h. The present FIA system was applicable to monitor the inactivation of catalase by glycation.
authors.affiliation: Department of Bioresources Science, Faculty of Agriculture, Kochi University, Monobe B-200, Nankoku 783-8502, Japan. hukeda@cc.kochi-u.ac.jp
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Ukeda
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Adachi
authors.forename: Masayoshi
authors.initials: M
authors.lastname: Sawamura
mesh_terms: D002138:Calibration; D002374:Catalase / Q000032:analysis*; D004800:Enzymes, Immobilized; D017022:Flow Injection Analysis; D006861:Hydrogen Peroxide / Q000737:chemistry; D007202:Indicators and Reagents; D010100:Oxygen / Q000032:analysis
chemical_list: D004800:Enzymes, Immobilized; D007202:Indicators and Reagents; D006861:Hydrogen Peroxide; D002374:Catalase; D010100:Oxygen