Purification and Properties of a Phytate-degrading Enzyme from <Emphasis Type="Italic">Pantoea agglomerans</Emphasis> |
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Authors: | Email author" target="_blank">Ralf?GreinerEmail author |
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Institution: | (1) Center for Molecular Biology, Federal Research Center for Nutrition and Food, Haid-und-Neu-Strasse 9, D-76131 Karlsruhe, Germany |
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Abstract: | A periplasmatic phytate-degrading enzyme from Pantoea agglomerans isolated from soil was purified about 470-fold to apparent homogeneity with a recovery of 16% referred to the phytate-degrading activity in the crude extract. It behaved as a monomeric protein with a molecular mass of about 42 kDa. The purified enzyme exhibited a single pH optimum at 4.5. Optimum temperature for the degradation of phytate was 60°C. The kinetic parameters for the hydrolysis of sodium phytate were determined to be KM = 0.34 mmol/l and kcat = 21 s-1 at pH 4.5 and 37°C. The enzyme exhibited a narrow substrate selectivity. Only phytate and glucose-1-phosphate were identified as good substrates. Since this Pantoea enzyme has a strong preference for glucose-1-phosphate over phytate, under physiological conditions glucose-1-phosphate is its most likely substrate. The maximum amount of phosphate released from phytate by the purified enzyme suggests myo-inositol pentakisphosphate as the final product of enzymatic phytate degradation. |
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Keywords: | Pantoea agglomerans phytase phytate phytate-degrading enzyme |
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