Biocatalysis, the use of enzymes to produce chemicals, offers numerous advantages over traditional organic chemistry. The most important ones are the excellent regio-, chemo-, and stereoselectivities that can be achieved, the high functional group tolerance, and the fact that biocatalytic transformations can usually be carried out in pure water. In this work, we have applied a semipurified aminopeptidase from Aspergillus oryzae (LAP2) for the chiral resolution of racemic piperazine-2-carboxamide into enantiopure (S)-piperazine-2-carboxylic acid. After characterizing the free enzyme, we also achieved its first immobilization at high loadings (>20 mg_protein/g_support) by testing different commercially available methacrylic resins. The immobilized catalyst showed 48–67% of retained activity and could be reused for more than 10 cycles in batch without any apparent loss of activity. Moreover, we also integrated the immobilized enzyme into continuous flow mode, which led to a significant increase in productivity and allowed continuous operation for more than 24 h without affecting the reaction yield.

中文翻译：

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生物催化剂固定化和工艺强化：(S)-哌嗪-2-甲酸二盐酸盐的生产

生物催化，即利用酶来生产化学品，与传统有机化学相比具有许多优势。最重要的是可以实现的优异的区域选择性、化学选择性和立体选择性、高官能团耐受性以及生物催化转化通常可以在纯水中进行这一事实。在这项工作中，我们应用来自米曲霉(LAP2) 的半纯化氨肽酶将外消旋哌嗪-2-甲酰胺手性拆分成对映体纯 ( S )-哌嗪-2-羧酸。在表征游离酶后，我们还通过测试不同的市售甲基丙烯酸树脂实现了其在高负载量（> 20 mg_蛋白质/g_支持物）下的首次固定。固定化催化剂显示出 48-67% 的保留活性，并且可以批量重复使用 10 次以上，而没有任何明显的活性损失。此外，我们还将固定化酶集成到连续流动模式中，这使得生产率显着提高，并允许连续运行超过24小时而不影响反应产率。