Dirigent isoflavene-forming PsPTS2: 3D structure, stereochemical, and kinetic characterization comparison with pterocarpan-forming PsPTS1 homolog in pea
作者:Qingyan Meng、Syed G.A. Moinuddin、Rhodesia M. Celoy、Clyde A. Smith、Robert P. Young、Michael A. Costa、Rachel A. Freeman、Masashi Fukaya、Doo Nam Kim、John R. Cort、Martha C. Hawes、Hans D. van Etten、Pankaj Pandey、Amar G. Chittiboyina、Daneel Ferreira、Laurence B. Davin、Norman G. Lewis
DOI:10.1016/j.jbc.2024.105647
日期:2024.3
were determined using NMR spectroscopy, electronic circular dichroism, and molecular orbital analyses. PsPTS2 efficiently converted -(3,4)-DMDI into DMDIF 20-fold faster than the -(3,4)-isomer. The 4-configured substrate’s near β-axial OH orientation significantly enhanced its leaving group abilities in generating A-ring mono-quinone methide (QM), whereas 4-isomer’s α-equatorial-OH was a poorer leaving
豌豆植物抗毒素 (−)-maackiain 和 (+)-pisatin 具有相反的 C6a/C11a 构型,但在生物合成上如何发生这种情况尚不清楚。豌豆直接蛋白 (DP) PsPTS2 生成 7,2ʹ-二羟基-4ʹ,5ʹ-亚甲基二氧基异黄烷-3-烯 (DMDIF),并对四种可能的 7,2ʹ-二羟基-4ʹ,5ʹ-亚甲基二氧基异黄烷-4-醇 (DMDI) 具有立体选择性)立体异构体进行了研究。使用核磁共振光谱、电子圆二色性和分子轨道分析确定立体异构体构型。 PsPTS2 有效地将 -(3,4)-DMDI 转化为 DMDIF,速度比 -(3,4)-异构体快 20 倍。 4-构型底物的近β轴OH取向显着增强了其生成A环单醌甲基化物(QM)的离去基团能力,而4-异构体的α-赤道-OH是较差的离去基团。对接模拟表明4-构型的β-轴向OH距离Asp最近,而4-异构体的α-赤道OH距离更远。 -(3,4)-