ABSTRACT
Comamonas testosteroni
TA441 utilizes testosterone via aromatization of the A ring followed by
meta
-cleavage of the ring. The product of the
meta
-cleavage reaction, 4,5-9,10-diseco-3-hydroxy-5,9,17-trioxoandrosta-1(10),2-dien-4-oic acid, is degraded by a hydrolase, TesD. We directly isolated and identified two products of TesD as 9,17-dioxo-1,2,3,4,10,19-hexanorandrostan-5-oic acid and (2
Z
,4
Z
)-2-hydroxyhexa-2,4-dienoic acid. The latter was a pure 4
Z
isomer. 2-Hydroxyhexa-2,4-dienoic acid was converted by a hydratase, TesE, and the product isolated from the reaction solution was identified as 2-hydroxy-4-hex-2-enolactone, indicating the direct product of TesE to be 4-hydroxy-2-oxohexanoic acid.
摘要
睾酮酵母菌
TA441 通过 A 环的芳香化作用利用睾酮,然后通过
元
-环的芳香化作用。其产物
元
-元清除反应的产物 4,5-9,10-二癸-3-羟基-5,9,17-三氧雄甾烷-1(10),2-二烯-4-酸会被水解酶 TesD 降解。我们直接分离并鉴定了 TesD 的两种产物,即 9,17-二氧代-1,2,3,4,10,19-己雄烷-5-酸和 (2
Z
,4
Z
)-2-羟基己-2,4-二烯酸。后者是一种纯净的 4
Z
异构体。2-羟基六-2,4-二烯酸在氢化酶 TesE 的作用下发生转化,从反应溶液中分离出来的产物被鉴定为 2-羟基-4-己-2-烯内酯,这表明 TesE 的直接产物是 4-羟基-2-氧代己酸。