Banana Peel Oxalate Oxidase-detection, Purification, Characterization and Physiological Role

Objective: Enzymes like oxalate oxidase (EC 1.2.3.4) and superoxide dismutase (EC 1.15.1.1) from germin family are known to generate active oxygen species. In the mammalian system, excess accumulations of oxalate causes kidney stones. Oxalate oxidase, an H2O2-generating enzyme, used for detection of oxalate. The aim of the present work is to screen out the activity of enzymes from all three stages of banana (Musa paradisica L. Variety “Bhusawal”) peel and to isolate, purified and characterized oxalate oxidase from this. With that describe the physiological role of both oxalate oxidase and superoxide dismutase in the plant. Methods: Oxalate oxidase activity can be detected directly in SDS-PAGE gel. Purification was done by using ion-exchange chromatography and SDSPAGE Gel. Results: Highest activity 5.99+0.021 unit /mg of oxalate oxidase were detected in leaky ripe stage of banana peel after purification. In crude extract of unripe banana peel activity of superoxide dismutase were found high (2.41unit/mg) compared to oxalate oxidase (0.269+ 0.020 unit/mg). Their occurence in different ripening stage of banana peel shows its role in plant defense mechanism. Conclusion: The purified enzyme of oxalate oxidase from banana peel is useful in the determination of oxalate content in common food, which is necessary for the prescription of the low oxalate diet for a patient with urinary and kidney stone where as superoxide dismutase work against ageing.