title: Dephosphorylation of phytate by using the Aspergillus niger phytase with a high affinity for phytate.
abstract: A phytase (EC 3.1.3.8) with a high affinity for phytic acid was found in Aspergillus niger SK-57 and purified to homogeneity in four steps by using ion-exchange chromatography (two types), gel filtration, and chromatofocusing. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of the purified enzyme gave a single stained band at a molecular mass of approximately 60 kDa. The Michaelis constant of the enzyme for phytic acid (18.7 +/- 4.6 microM) was statistically analyzed. In regard to the orthophosphate released from phytic acid, a significant difference between a low K(m) phytase from A. niger SK-57 and a high K(m) phytase from Aspergillus ficuum was recognized.
authors.affiliation: Research and Development, Shin Nihon Chemical Co., Ltd., Anjo, Aichi 446-0063, Japan. nagashma@d1.dion.ne.jp
authors.forename: T
authors.initials: T
authors.lastname: Nagashima
authors.forename: T
authors.initials: T
authors.lastname: Tange
authors.forename: H
authors.initials: H
authors.lastname: Anazawa
mesh_terms: D010832:6-Phytase / Q000378:metabolism*; D001234:Aspergillus niger / Q000201:enzymology*; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D010766:Phosphorylation; D010833:Phytic Acid / Q000378:metabolism*
chemical_list: D010833:Phytic Acid; D010832:6-Phytase