EC |
1.1.1.206 |
Accepted name: |
tropinone reductase I |
Reaction: |
tropine + NADP+ = tropinone + NADPH + H+ |
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For diagram of reaction, click here |
Glossary: |
tropine = 3α-hydroxytropane = tropan-3-endo-ol |
Other name(s): |
tropine dehydrogenase; tropinone reductase (ambiguous); TR-I |
Systematic name: |
tropine:NADP+ 3α-oxidoreductase |
Comments: |
Also oxidizes other tropan-3α-ols, but not the corresponding β-derivatives [1]. This enzyme along with EC 1.1.1.236, tropinone reductase II, represents a branch point in tropane alkaloid metabolism [4]. Tropine (the product of EC 1.1.1.206) is incorporated into hyoscyamine and scopolamine whereas pseudotropine (the product of EC 1.1.1.236) is the first specific metabolite on the pathway to the calystegines [4]. Both enzymes are always found together in any given tropane-alkaloid-producing species, have a common substrate, tropinone, and are strictly stereospecific [3]. |
Links to other databases: |
BRENDA, EXPASY, KEGG, MetaCyc, PDB, CAS registry number: 118390-87-7 |
References: |
1. |
Koelen, K.J. and Gross, G.G. Partial purification and properties of tropine dehydrogenase from root cultures of Datura stramonium. Planta Med. 44 (1982) 227–230. [PMID: 17402126] |
2. |
Couladis, M.M, Friesen, J.B., Landgrebe, M.E. and Leete, E. Enzymes catalysing the reduction of tropinone to tropine and ψ-tropine isolated from the roots of Datura innoxia. Pytochemistry 30 (1991) 801–805. |
3. |
Nakajima, K., Hashimoto, T. and Yamada, Y. Two tropinone reductases with different stereospecificities are short-chain dehydrogenases evolved from a common ancestor. Proc. Natl. Acad. Sci. USA 90 (1993) 9591–9595. [DOI] [PMID: 8415746] |
4. |
Dräger, B. Tropinone reductases, enzymes at the branch point of tropane alkaloid metabolism. Phytochemistry 67 (2006) 327–337. [DOI] [PMID: 16426652] |
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[EC 1.1.1.206 created 1984, modified 2007] |
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