title: Enzymatic activity and partial purification of solanapyrone synthase: first enzyme catalyzing Diels-Alder reaction.
abstract: In cell-free extracts of Alternaria solani, an enzymatic activity converting prosolanapyrone II to solanapyrones A and D via oxidation and subsequent Diels-Alder reaction has been found. Chromatography with DEAE-Sepharose provided two active fractions, pools 1 and 2. The former fraction converted prosolanapyrone II to solanapyrones A and D in a ratio of 2.2:1 with optical purities of 99% and 45% ee, respectively. The latter fraction did so in a ratio of 7.6:1 with 99% and nearly 0% ee, respectively. The enzyme partially purified from pool 2 native molecular weight of 40-62 kD and a pl of 4.25. The high reactivity of prosolanapyrone III in aqueous solution and the chromatographic behavior of the enzyme in pool 2 suggest that a single enzyme catalyzes both the oxidation and Diels-Alder reaction.
authors.affiliation: Department of Bioscience and Chemistry, Faculty of Agriculture, Hokkaido University, Sapporo, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Katayama
authors.forename: T
authors.initials: T
authors.lastname: Kobayashi
authors.forename: H
authors.initials: H
authors.lastname: Oikawa
authors.forename: M
authors.initials: M
authors.lastname: Honma
authors.forename: A
authors.initials: A
authors.lastname: Ichihara
mesh_terms: D000429:Alcohol Oxidoreductases / Q000378:metabolism; D000528:Alternaria / Q000201:enzymology* / Q000378:metabolism; D006863:Hydrogen-Ion Concentration; D019746:Intramolecular Oxidoreductases / Q000737:chemistry / Q000302:isolation & purification*; D008970:Molecular Weight; D009281:Naphthalenes / Q000737:chemistry / Q000378:metabolism*; D011753:Pyrones / Q000737:chemistry / Q000378:metabolism*
chemical_list: D009281:Naphthalenes; D011753:Pyrones; C113269:solanapyrone B; C113266:solanapyrone A; D000429:Alcohol Oxidoreductases; C019643:alcohol oxidase; D019746:Intramolecular Oxidoreductases; C113265:solanapyrone synthase