Guo L, Dixon R A, Paiva N L
Plant Biology Division, Samuel Roberts Noble Foundation, Ardmore, OK 73402.
FEBS Lett. 1994 Dec 19;356(2-3):221-5. doi: 10.1016/0014-5793(94)01267-9.
Vestitone reductase and 7,2'-dihydroxy-4'-methoxy-isoflavanol (DMI) dehydratase are the two final enzymes in medicarpin biosynthesis in alfalfa (Medicago sativa). Although two independent enzymes, vestitone reductase and DMI dehydratase can be loosely associated in low ionic strength buffers, presumably by a weak protein-protein interaction. The activities of vestitone reductase and DMI dehydratase increased approximately 3-fold 6 hours after elicitor treatment in alfalfa suspension cell culture. The activities remained at maximal levels for 40 hours, correlating with a steady increase in the medicarpin content of the cells. Medicarpin produced in vitro from vestitone by the action of vestitone reductase and DMI dehydratase was found to be (-)-medicarpin (6aR,11aR-medicarpin), possessing the same stereochemistry as medicarpin produced in vivo.
紫苜蓿素还原酶和7,2'-二羟基-4'-甲氧基异黄酮醇（DMI）脱水酶是紫花苜蓿（Medicago sativa）中苜蓿素生物合成的两种最终酶。尽管是两种独立的酶，但紫苜蓿素还原酶和DMI脱水酶在低离子强度缓冲液中可能通过弱蛋白质-蛋白质相互作用而松散结合。在苜蓿悬浮细胞培养中，激发子处理6小时后，紫苜蓿素还原酶和DMI脱水酶的活性增加了约3倍。这些活性在40小时内保持在最高水平，这与细胞中苜蓿素含量的稳定增加相关。通过紫苜蓿素还原酶和DMI脱水酶的作用，由紫苜蓿素体外产生的苜蓿素被发现是（-）-苜蓿素（6aR,11aR-苜蓿素），其立体化学与体内产生的苜蓿素相同。
