Enzymatic activity and partial purification of solanapyrone synthase: first enzyme catalyzing Diels-Alder reaction.
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.
Katayama
K
K
Department of Bioscience and Chemistry, Faculty of Agriculture, Hokkaido University, Sapporo, Japan.
Kobayashi
T
T
Oikawa
H
H
Honma
M
M
Ichihara
A
A
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*
D009281:Naphthalenes; D011753:Pyrones; C113269:solanapyrone B; C113266:solanapyrone A; D000429:Alcohol Oxidoreductases; C019643:alcohol oxidase; D019746:Intramolecular Oxidoreductases; C113265:solanapyrone synthase