Purification and characterization of a phytate-degrading enzyme from germinated oat (Avena sativa)

✍ Scribed by Greiner, Ralf; Alminger, Marie Larsson

• Publisher: John Wiley and Sons
• Year: 1999
• Tongue: English
• Weight: 118 KB
• Volume: 79
• Category: Article
• ISSN: 0022-5142
• DOI: 10.1002/(sici)1097-0010(199908)79:11<1453::aid-jsfa386>3.0.co;2-r

✦ Synopsis

A phytate-degrading enzyme (myo-inositol hexakisphosphate phosphohydrolase) has been puri®ed about 5,400-fold from germinated oat seedlings to apparent homogeneity. The molecular mass of the native monomeric enzyme was estimated to be about 67 kDa. Optimal pH for degradation of phytate was 5.0 and the optimal temperature 38 °C. Kinetic parameters for the hydrolysis of Na-phytate are K M 30 mM and k cat 356 s À1 at 35 °C and pH 5.0. The oat phytase exhibits a broad af®nity for various phosphorylated compounds and hydrolyses phytate in a stepwise manner. The ®rst hydrolysis product was identi®ed as D/L-l(1,2,3,4,5) P 5 .