Graduate School of Life Sciences, Ritsumeikan University, Kusatsu, Shiga 525-8577, Japan.
Medical Biochemistry, Kurume University School of Medicine, Kurume, Fukuoka 830-0011, Japan.
Bioorg Med Chem Lett. 2021 May 15;40:127931. doi: 10.1016/j.bmcl.2021.127931. Epub 2021 Mar 9.
Green photosynthetic bacteria with an efficient light-harvesting system contain special chlorophyll molecules, called bacteriochlorophylls c, d, e, in their main antennae. In the biosynthetic pathway, a BciC enzyme is proposed to catalyze the hydrolysis of the C13-methoxycarbonyl group of chlorophyllide a, but the resulting C13-carboxy group has not been detected yet because it is spontaneously removed due to the instability of the β-keto-carboxylic acid. In this study, the in vitro BciC enzymatic reactions of zinc methyl (13R/S)-hydroxy-mesochlorophyllides a were examined and a carboxylic acid possessing the C13S-OH was first observed as the hydrolyzed product of the C13-COOCH.
具有高效光捕获系统的绿色光合细菌在其主天线中含有特殊的叶绿素分子，称为细菌叶绿素 c、d、e。在生物合成途径中，BciC 酶被提议催化叶绿素 a 的 C13-甲氧基羰基的水解，但由于β-酮羧酸的不稳定性，尚未检测到生成的 C13-羧基，因为它是自发去除的。在这项研究中，检查了锌甲酯（13R/S）-羟基-中胆素 a 的体外 BciC 酶促反应，首次观察到具有 C13S-OH 的羧酸作为 C13-COOCH 的水解产物。
