Femmer Christian, Bechtold Matthias, Roberts Tania Michelle, Panke Sven
ETH Zurich, Department of Biosystems Science and Engineering, Mattenstrasse 26, 4058, Basel, Switzerland.
Appl Microbiol Biotechnol. 2016 Sep;100(17):7423-36. doi: 10.1007/s00253-016-7729-8. Epub 2016 Jul 22.
Chiral resolutions of racemic mixtures are limited to a theoretical yield of 50 %. This yield can be doubled by integration of a step-wise or continuous racemization of the non-desired enantiomer. Many of the different routes along which the racemization step can be conducted require harsh treatments and are therefore often incompatible with the highly functionalized state of many compounds relevant for the life science industries. Employing enzymatic catalysis for racemization can therefore be highly beneficial. Racemases allow racemization in one reaction step. Most representatives from this group are found in the domain of amino acid or amino acid derivative racemization, with few other examples, notably the racemization of mandelic acid. Corresponding to the importance of enantiospecific conversion of amino acid precursor racemates for the production of enantiopure amino acids, the most important biotechnological use for racemases is the racemization of such precursors. However, alternative uses, in particular for mandelate and amino acid racemases, are emerging. Here, we summarize the natural roles of racemases and their occurrence, the applications, and the biochemistry and engineering of this promising class of biocatalysts.
外消旋混合物的手性拆分理论产率限制为50%。通过将不需要的对映体进行逐步或连续消旋化，可以使产率翻倍。进行消旋化步骤的许多不同途径需要苛刻的处理条件，因此通常与生命科学产业中许多相关化合物的高官能化状态不相容。因此，采用酶催化进行消旋化可能非常有益。消旋酶可在一个反应步骤中实现消旋化。该类别的大多数代表存在于氨基酸或氨基酸衍生物消旋化领域，其他例子很少，特别是扁桃酸的消旋化。对应于氨基酸前体消旋体的对映体特异性转化对于生产对映体纯氨基酸的重要性，消旋酶最重要的生物技术用途是此类前体的消旋化。然而，其他用途正在出现，特别是对于扁桃酸消旋酶和氨基酸消旋酶。在此，我们总结了消旋酶的天然作用及其存在情况、应用以及这类有前景的生物催化剂的生物化学和工程学。
