Tropinone reductase II explained

tropinone reductase
Ec Number:	1.1.1.236
Cas Number:	136111-61-0
Go Code:	0050358

In enzymology, a tropinone reductase II is an enzyme that catalyzes the chemical reaction

pseudotropine + NADP⁺

\rightleftharpoons tropinone + NADPH + H⁺

Thus, the two substrates of this enzyme are pseudotropine and NADP⁺, whereas its 3 products are tropinone, NADPH, and H⁺.

This enzyme belongs to the family of oxidoreductases, specifically those acting on the CH-OH group of donor with NAD⁺ or NADP⁺ as acceptor. The systematic name of this enzyme class is pseudotropine:NADP⁺ 3-oxidoreductase. Other names in common use include tropinone (psi-tropine-forming) reductase, pseudotropine forming tropinone reductase, tropinone reductase (ambiguous), and TR-II. This enzyme participates in alkaloid biosynthesis ii.

Structural studies

As of late 2007, 6 structures have been solved for this class of enzymes, with PDB accession codes,,,,, and .

References

• Drager B, Hashimoto T, Yamada Y . 1988 . Purification and characterization of pseudotropine forming tropinone reductase from Hyoscyamus niger root cultures . Agric. Biol. Chem. . 52 . 2663 - 2667 . 10.1271/bbb1961.52.2663 . 10 . free .
• Couladis MM, Friesen JB, Landgrebe ME, Leete E . 1991 . Enzymes catalysing the reduction of tropinone to tropine and ψ-tropine isolated from the roots of Datura innoxia . Phytochemistry . 30 . 801 - 805 . 10.1016/0031-9422(91)85255-X . 3 . 1991PChem..30..801C .
• Nakajima K, Hashimoto T, Yamada Y . 1993 . Two tropinone reductases with different stereospecificities are short-chain dehydrogenases evolved from a common ancestor . Proc. Natl. Acad. Sci. U.S.A. . 90 . 9591 - 5 . 8415746 . 10.1073/pnas.90.20.9591 . 20 . 47615 . 1993PNAS...90.9591N . free .
• Drager B . 2006 . Tropinone reductases, enzymes at the branch point of tropane alkaloid metabolism . . 67 . 327 - 37 . 16426652 . 10.1016/j.phytochem.2005.12.001 . 4 . 2006PChem..67..327D .