Institute of Molecular Biosciences, University of Graz, Humboldtstr. 50/3, Graz, A-8010, Austria.
Chem Soc Rev. 2011 Aug;40(8):4346-63. doi: 10.1039/c1cs15118e. Epub 2011 Jun 20.
B(12)-cofactors play important roles in the metabolism of microorganisms, animals and humans. Microorganisms are the only natural sources of B(12)-derivatives, and the latter are "vitamins" for other B(12)-requiring organisms. Some B(12)-dependent enzymes catalyze complex isomerisation reactions, such as methylmalonyl-CoA mutase. They need coenzyme B(12), an organometallic B(12)-derivative, to induce enzymatic radical reactions. Another group of widely relevant enzymes catalyzes the transfer of methyl groups, such as methionine synthase, which uses methylcobalamin as cofactor. This tutorial review covers structure and reactivity of B(12)-derivatives and structural aspects of their interactions with proteins and nucleotides, which are crucial for the efficient catalysis by the important B(12)-dependent enzymes, and for achieving and regulating uptake and transport of B(12)-derivatives.
B(12)-辅因子在微生物、动物和人类的代谢中发挥着重要作用。微生物是 B(12)-衍生物的唯一天然来源，而后者是其他 B(12)-需要的生物体的“维生素”。一些依赖 B(12)的酶催化复杂的异构化反应，如甲基丙二酰辅酶 A 变位酶。它们需要辅酶 B(12)，一种有机金属 B(12)-衍生物，来诱导酶促自由基反应。另一组广泛相关的酶催化甲基基团的转移，如蛋氨酸合酶，它使用甲基钴胺素作为辅因子。本教程综述涵盖了 B(12)-衍生物的结构和反应性，以及它们与蛋白质和核苷酸相互作用的结构方面，这些对于重要的依赖 B(12)的酶的高效催化，以及实现和调节 B(12)-衍生物的摄取和运输至关重要。
