title: Soybean lipoxygenases-1, -2a, -2b and -2c do not contain PQQ.
abstract: Soybean isoenzymes lipoxygenases-1, -2a, -2b and -2c were examined spectroscopically for the presence of covalently bound pyrrolo quinoline quinone (PQQ) after derivatization by phenylhydrazine (PH), 2,4-dinitrophenylhydrazine (DNPH) and 3-methyl-2-benzothiazolinone hydrazone (MBTH). DNPH derivatization of PQQ after a pronase digestion step of lipoxygenase-1 in the presence of an anion exchange gel fixing the cofactor was also investigated. None of these experiments provided evidence for the presence of PQQ contrary to previous report by Van der Meer et al (1). We have checked, by EPR spectroscopy, that the three reactants used were able to reduce the active site ferric iron. Our results were confirmed by the absence of enzyme inhibition by cis- and trans-1,2-diaminocyclohexane or benzylamine in the presence of NaBH3CN which have been reported to react with PQQ and to inactivate quinoproteins (2,3).
authors.affiliation: Laboratoire de Chimie et Biochimie Pharmacologiques et Toxicologiques, Université René Descartes, URA 400 CNRS, Paris France.
authors.forename: I
authors.initials: I
authors.lastname: Michaud-Soret
authors.forename: R
authors.initials: R
authors.lastname: Daniel
authors.forename: C
authors.initials: C
authors.lastname: Chopard
authors.forename: D
authors.initials: D
authors.lastname: Mansuy
authors.forename: C
authors.initials: C
authors.lastname: Cucurou
authors.forename: V
authors.initials: V
authors.lastname: Ullrich
authors.forename: J C
authors.initials: JC
authors.lastname: Chottard
mesh_terms: D052160:Benzothiazoles; D001596:Benzylamines / Q000494:pharmacology; D001665:Binding Sites; D003067:Coenzymes / Q000138:chemical synthesis / Q000737:chemistry*; D003514:Cyclohexylamines / Q000494:pharmacology; D004578:Electron Spin Resonance Spectroscopy; D006835:Hydrazones; D007527:Isoenzymes / Q000138:chemical synthesis / Q000737:chemistry*; D008084:Lipoxygenase / Q000138:chemical synthesis / Q000737:chemistry*; D045542:PQQ Cofactor; D010659:Phenylhydrazines / Q000138:chemical synthesis; D015363:Quinolones / Q000737:chemistry*; D013025:Glycine max / Q000187:drug effects / Q000201:enzymology*; D013056:Spectrophotometry, Ultraviolet; D013844:Thiazoles / Q000138:chemical synthesis
chemical_list: D052160:Benzothiazoles; D001596:Benzylamines; D003067:Coenzymes; D003514:Cyclohexylamines; D006835:Hydrazones; D007527:Isoenzymes; D010659:Phenylhydrazines; D015363:Quinolones; D013844:Thiazoles; C004787:2,4-dinitrophenylhydrazine; D045542:PQQ Cofactor; C030796:benzylamine; C030435:1,2-cyclohexanediamine; D008084:Lipoxygenase; C002536:3-methyl-2-benzothiazolone hydrazone