Stereospecificity of myo-inositol hexakisphosphate dephosphorylation by phytate-degrading enzymes of cereals

Using a combination of High-Performance Ion Chromatography analysis and kin etic studies the stereospecificity of myo-inositol hexakisphosphate dephosp horylation by the spelt phytase D21, the lye phytase, the barley phytases P 1 and P2, and the oat phytase was established. The data demonstrate that al l the cereal phytate-degrading enzymes under investigation dephosphorylate myoinositol hexakisphosphate in a stereospecific way by sequential removal of phosphate groups via D-Ins(1, 2, 3, 5, 6)P-5, D-Ins(1,2,5,6)P-4, D-Ins(1 , 2, 6)P-3, DIns(1,2)P-2 to finally Ins(2)P (notation 4 / 3 / 5 / 6 / 1).