Two‐step epoxidation of hyoscyamine to scopolamine is catalyzed by bifunctional hyoscyamine 6β‐hydroxylase

FEBS Letters

Yamada, Yasuyuki¹  Matsuda, Jun¹  Hashimoto, Takashi¹ 

[1]Department of Agricultural Chemistry, Faculty of Agriculture, Kyoto University, Sakyoku, Kyoto 606-01, Japan

关键词: Hyoscyamine 6β-hydroxylase;    Bacterial expression;    Epoxidation;    Scopolamine;   

DOI  :  10.1016/0014-5793(93)80187-Y

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

In several solanaceous plants, hyoscyamine is first hydroxylated at the 6β-position, and then epoxidized to scopolamine. We expressed hyoscyamine 6β-hydroxylase (H6H) in Escherichia coli as a fusion protein with maltose-binding protein. The crude cell extract from the bacterium that expressed the soluble fusion protein showed a strong hydroxylase activity and a weak epoxidase activity. When 100 μM of hyoscyamine was fed to the recombinant bacterium, the alkaloid was first converted to 6β-hydroxyhyoscyamine, and then to scopolamine, which was almost the only alkaloid found in the culture after one week. Therefore, H6H catalyzes two consecutive reactions that oxidize hyoscyamine to scopolamine.

【 授权许可】

Unknown