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The molecular cloning of dihydroartemisinic aldehyde reductase and its implication in artemisinin biosynthesis in Artemisia annua
Ryden, A.M. ; Ruyter-Spira, C.P. ; Quax, W.J. ; Hiroyuki, O. ; Toshiya, M. ; Kayser, O. ; Bouwmeester, H.J. - \ 2010
Planta Medica 76 (2010). - ISSN 0032-0943 - p. 1778 - 1783.
chain dehydrogenases/reductases sdrs - amorpha-4,11-diene synthase - key enzyme - functional assignments - expression - acid - identification - plants - dehydrogenase/reductase - terpenoids
A key point in the biosynthesis of the antimalarial drug artemisinin is the formation of dihydroartemisinic aldehyde which represents the key difference between chemotype specific pathways. This key intermediate is the substrate for several competing enzymes, some of which increase the metabolic flux towards artemisinin, and some of which - as we show in the present study - may have a negative impact on artemisinin production. In an effort to understand the biosynthetic network of artemisinin biosynthesis, extracts of A. annua flowers were investigated and found to contain an enzyme activity competing in a negative sense with artemisinin biosynthesis. The enzyme Red1 is a broad substrate oxidoreductase belonging to the short chain dehydrogenase/reductase family with high affinity for dihydroartemisinic aldehyde and valuable monoterpenoids. Spatial and temporal analysis of cDNA revealed Red1 to be trichome specific. The relevance of Red1 to artemisinin biosynthesis is discussed.
Molecular cloning and characterization of a broad substrate terpenoid oxidoreductase from Artemisia annua.
Ryden, A.M. ; Ruyter-Spira, C.P. ; Litjens, R. ; Takahashi, S. ; Quax, W.J. ; Osada, H. ; Bouwmeester, H.J. ; Kayser, O. - \ 2010
Plant and Cell Physiology 51 (2010)7. - ISSN 0032-0781 - p. 1219 - 1228.
chain dehydrogenases/reductases sdrs - amorpha-4,11-diene synthase - functional assignments - biosynthetic-pathway - essential oil - key enzyme - expression - reductase - peppermint - acid
From Artemisia annua L., a new oxidoreductase (Red 1) was cloned, sequenced and functionally characterized. Through bioinformatics, heterologous protein expression, and enzyme substrate conversion assays, the elucidation of the enzymatic capacities of Red1 was achieved. Red1 acts on monoterpenoids, and in particular functions as a menthone:neomenthol oxidoreductase. The kinetic parameter kcat/Km was determined to be 939 fold more efficient for the reduction of (-)-menthone to (+)-neomenthol, than results previously reported for the menthone:neomenthol reductase from Mentha x piperita. Based on its kinetic properties, the possible use of Red1 in biological crop protection is discussed.