title: Colorimetric determination of pyrophosphate anion and its application to adenylation enzyme assay.
abstract: A colorimetric pyrophosphate assay based on the formation and reduction of the 18-molybdopyrophosphate ([(P2O7)Mo18O54](4-)) anion in an acetonitrile-water mixed solvent was modified and improved. The [(P2O7)Mo18O54](4-) anion is precipitated from the acetonitrile-water solution containing MoO4(2-) and HCl, and is re-dissolved in neat acetonitrile or propylene carbonate. This separation process decreases the interference by ATP, and prevents a yellow coloration of the reducing agent, ascorbic acid, due to excess Mo(VI) species. In the organic solvent, the [(P2O7)Mo18O54](4-) anion is reduced to a more intense blue molybdopyrophosphate species. The application of the colorimetry to the assay of adenylation enzymes is also described in this note.
authors.affiliation: Faculty of Biotechnology, Fukui Prefectural University.
authors.forename: Hajime
authors.initials: H
authors.lastname: Katano
authors.forename: Hiro
authors.initials: H
authors.lastname: Watanabe
authors.forename: Masahiro
authors.initials: M
authors.lastname: Takakuwa
authors.forename: Chitose
authors.initials: C
authors.lastname: Maruyama
authors.forename: Yoshimitsu
authors.initials: Y
authors.lastname: Hamano
mesh_terms: D003124:Colorimetry; D011756:Diphosphates / Q000032:analysis* / Q000378:metabolism; D007477:Ions / Q000032:analysis / Q000378:metabolism; D010453:Peptide Synthases / Q000378:metabolism*
chemical_list: D011756:Diphosphates; D007477:Ions; C107241:diphosphoric acid; D010453:Peptide Synthases; C104385:non-ribosomal peptide synthase