20298-97-9Relevant academic research and scientific papers
The pathway of dephosphorylation of myo-inositol hexakisphosphate by phytases from wheat bran of Triticum aestivum L. cv. Nourin #61
Nakano, Tadao,Joh, Toshio,Narita, Kazumasa,Hayakawa, Toshiro
, p. 995 - 1003 (2000)
Phytases are the primary enzymes responsible for the hydrolysis of phytic acid, myo-inositol-1, 2, 3, 4, 5, 6-hexakisphosphate (InsP6). The pathway of hydrolysis of InsP6 by phytase from wheat bran of Triticum aestivum L. cv. Nourin #61 is proved in this study. Structures of the intermediates were established by a variety of nuclear magnetic resonance techniques (1H-, two-dimensional 1H-1H coupling-correlation spectra and two-dimensional 31P-1H correlation spectra), gas chromatography, and bioassay. On the basis of the structures identified, initial hydrolysis of the phosphate ester occurs at the D/L-4 position of InsP6 to yield D/L-Ins (1, 2, 3, 5, 6) P5. After the dephosphorylation, the pathway of dephosphorylation is divided into two routes. The main route proceeds via D/L-Ins (1, 2, 5, 6) P4, D/L-Ins (1, 2, 6) P3 and D/L-Ins (1, 2) P2, while the minor route proceeds via D/L-Ins (1, 2, 3, 6) P4, Ins (1, 2, 3) P3 and D/L-Ins (1, 2) P2. D/L-Ins (1, 2) P2 is hydrolyzed at the D/L-1 or 2-position, and finally myo-inositol is produced.
Quantitative analysis of phytate globoids isolated from wheat bran and characterization of their sequential dephosphorylation by wheat phytase
Bohn, Lisbeth,Josefsen, Lone,Meyer, Anne S.,Rasmussen, Soren K.
, p. 7547 - 7552 (2008/09/19)
Wheat phytase was purified to investigate the action of the enzyme toward its pure substrate (phytic acid - myo-inositol hexakisphosphate) and its naturally occurring substrate (phytate globoids). Phytate globoids were purified to homogeneity from wheat bran, and their nutritionally relevant parameters were quantified by ICP-MS. The main components of the globoids were phytic acid (40% w/w), protein (46% w/w), and several minerals, in particular, K > Mg > Ca > Fe (in concentration order). Investigation of enzyme kinetics revealed that Km and Vmax decreased by 29 and 37%, respectively, when pure phytic acid was replaced with phytate globoids as substrate. Time course degradation of phytic acid or phytate globoids using purified wheat phytase was followed by HPIC identification of inositol phosphates appearing and disappearing as products. In both cases, enzymatic degradation initiated at both the 3- and 6-positions of phytic acid and end products were inositol and phosphate.
