Development of Sensor for ATPase Activity

Abstract

The enzyme sensor for ATPase activity consisted of an immobilized membrane of two enzymes, purine nucleoside phosphorylase and xanthine oxidase, and an oxygen electrode. The optimum conditions for using the sensor were as follows; temperature, 32°C; pH, 7.0; flow rate of buffer, 0.4 ml/min; flow rate of substrate, 0.6 ml/min; inosine concentration, 0.2 mg/ml; ATP concentration, 0.04 mg/ml; and sample volume; 40, μl: ATPase activity in fish serum measured by the proposed sensor system was in good agreement with activity determined by a conventional colorimetric method. Correlation coefficient was 0.986. One assay could be completed within 3 min. Continuous determination was possible for 80 min (16 assays). The mean current output was 0.28 μA and standard deviation was ±0.25%.