Indian Journal of Chemical Technology, Vol.11, No.4, 495-499, 2004
Preparation of a reusable strip of barley oxalate oxidase for determination of urinary oxalate
A reusable strip of oxalate oxidase was prepared by immobilizing covalently, a partially purified barley oxalate oxidase on alkylamine glass beads affixed on a plastic strip with a non-reactive fixative. The immobilized enzyme gave a conjugation yield of 9.5 mg g(-1) support with 84.8% retention of initial activity of free enzyme. A method for discrete analysis of oxalate in urine was developed employing this enzyme strip. The method is based on measurement of H2O2 generated from urinary oxalate by strip bound oxalate oxidase by Trinder's colour reaction. The minimum detection limit of the method was 0.9 mug 0.1 mL(-1) urine. The recovery of added oxalate was 84.7%. Within and between assay co-efficient of variation were <7.3% and <15.6.% respectively. A fair correlation (r=0.752) was found between oxalate values obtained by a commercial kit method and present method. The method provides enormous case in handling of immobilized enzyme during its reuse and is unaffected by Cl- found in biological fluids.