Inositol Phosphate Phosphatases of Microbiological Origin.Observations on the Nature of the Active Centre of a Bacterial (Pseudomonas Sp.) Phytase

Abstract

The pentaphosphates produced by a bacterial phytase acting on myo- and I,-ckiro-inositol hexaphosphates as substrates were identified by ion-exchange chromatography. On the basis of the structures of these pentaphosphates and the previously published properties of the bacterial phytase, a simple model for the active centre of the enzyme is proposed which is capable of explaining the intermediates, as far as the diphosphate stage, isolated by Cosgrove from the hydl'olysates of myo·, D.ckiro-, and 8cyllo-inositol hexaphosphates due to the action of this enzyme. With slight modification this model for the active centre is also capable of explaining, as far as the diphosphate stage, the intermediates isolated by Tomlinson and Ballou from the hydrolysate of myo·inositol hexaphosphate by wheat-bran phytase