Nowicka Beatrycze, Kruk Jerzy
Department of Plant Physiology and Biochemistry, Faculty of Biochemistry, Biophysics and Biotechnology, Jagiellonian University, Gronostajowa 7, 30-387 Kraków, Poland.
Biochim Biophys Acta. 2010 Sep;1797(9):1587-605. doi: 10.1016/j.bbabio.2010.06.007. Epub 2010 Jun 19.
Isoprenoid quinones are one of the most important groups of compounds occurring in membranes of living organisms. These compounds are composed of a hydrophilic head group and an apolar isoprenoid side chain, giving the molecules a lipid-soluble character. Isoprenoid quinones function mainly as electron and proton carriers in photosynthetic and respiratory electron transport chains and these compounds show also additional functions, such as antioxidant function. Most of naturally occurring isoprenoid quinones belong to naphthoquinones or evolutionary younger benzoquinones. Among benzoquinones, the most widespread and important are ubiquinones and plastoquinones. Menaquinones, belonging to naphthoquinones, function in respiratory and photosynthetic electron transport chains of bacteria. Phylloquinone K(1), a phytyl naphthoquinone, functions in the photosynthetic electron transport in photosystem I. Ubiquinones participate in respiratory chains of eukaryotic mitochondria and some bacteria. Plastoquinones are components of photosynthetic electron transport chains of cyanobacteria and plant chloroplasts. Biosynthetic pathway of isoprenoid quinones has been described, as well as their additional, recently recognized, diverse functions in bacterial, plant and animal metabolism.
类异戊二烯醌是存在于生物体膜中的最重要的化合物组之一。这些化合物由一个亲水头基和一个非极性类异戊二烯侧链组成，赋予分子脂溶性特征。类异戊二烯醌主要在光合和呼吸电子传递链中作为电子和质子载体发挥作用，并且这些化合物还具有其他功能，如抗氧化功能。大多数天然存在的类异戊二烯醌属于萘醌或进化上较新的苯醌。在苯醌中，分布最广且最重要的是泛醌和质体醌。属于萘醌的甲基萘醌在细菌的呼吸和光合电子传递链中起作用。叶绿醌K(1)，一种植基萘醌，在光系统I的光合电子传递中起作用。泛醌参与真核线粒体和一些细菌的呼吸链。质体醌是蓝细菌和植物叶绿体光合电子传递链的组成部分。类异戊二烯醌的生物合成途径已被描述，以及它们最近在细菌、植物和动物代谢中被认识到的其他多样功能。
