Department of Biological Chemistry, University of Michigan Medical Center, Ann Arbor, MI 48109-0600, USA.
J Biol Chem. 2013 May 10;288(19):13186-93. doi: 10.1074/jbc.R113.458810. Epub 2013 Mar 28.
The reactivity of the cobalt-carbon bond in cobalamins is the key to their chemical versatility, supporting both methyl transfer and isomerization reactions. During evolution of higher eukaryotes that utilize vitamin B12, the high reactivity of the cofactor coupled with its low abundance pressured development of an efficient system for uptake, assimilation, and delivery of the cofactor to client B12-dependent enzymes. Although most proteins suspected to be involved in B12 trafficking were discovered by 2009, the recent identification of a new protein reveals that the quest for elucidating the intracellular B12 highway is still far from complete. Herein, we review the biochemistry of cobalamin trafficking.
钴胺素中钴-碳键的反应活性是其化学多功能性的关键，支持甲基转移和异构化反应。在利用维生素 B12 的高等真核生物的进化过程中，由于辅助因子的高反应活性及其低丰度，因此需要开发一种有效的系统来摄取、同化和将辅助因子递送至客户 B12 依赖性酶。尽管到 2009 年为止，已经发现了大多数疑似参与 B12 运输的蛋白质，但最近发现的一种新蛋白质表明，阐明细胞内 B12 高速公路的探索仍远未完成。在此，我们回顾了钴胺素运输的生物化学。
