acib GmbH, Petersgasse 14, 8010, Graz, Austria.
Present address: School of Food and Nutritional Sciences, University College Cork, College Road, Cork, Ireland.
Chembiochem. 2018 Feb 16;19(4):312-316. doi: 10.1002/cbic.201700419. Epub 2017 Dec 11.
Hydroxynitrile lyase from the white rabbit's foot fern Davallia tyermannii (DtHNL) catalyzes the enantioselective synthesis of α-cyanohydrins, which are key building blocks for pharmaceutical and agrochemical industries. An efficient and competitive process necessitates the availability and robustness of the biocatalyst. Herein, the recombinant production of DtHNL1 in Komagataella phaffii, yielding approximately 900 000 U L , is described. DtHNL1 constitutes approximately 80 % of the total protein content. The crude enzyme was immobilized. Crosslinked enzyme aggregates (CLEAs) resulted in significant enhancement of the biocatalyst stability under acidic conditions (activity retained after 168 h at pH 2.4). The DtHNL1-CLEA was employed for (R)-mandelonitrile synthesis (99 % conversion, 98 % enantiomeric excess) in a biphasic system, and evaluated for the synthesis of (R)-hydroxypivaldehyde cyanohydrin under reaction conditions that immediately inactivated non-immobilized DtHNL1. The results show the DtHNL1-CLEA to be a stable biocatalyst for the synthesis of enantiomerically pure cyanohydrins under acidic conditions.
来自兔脚蕨 Davallia tyermannii（DtHNL）的羟腈裂解酶催化对映选择性合成α-氰醇，这是制药和农用化学品行业的关键构建块。高效和有竞争力的过程需要生物催化剂的可用性和稳健性。本文描述了 Komagataella phaffii 中 DtHNL1 的重组生产，产量约为 900000U/L。DtHNL1 约占总蛋白质含量的 80%。粗酶被固定化。交联酶聚集体（CLEAs）在酸性条件下显著提高了生物催化剂的稳定性（在 pH 2.4 下保持 168 小时后仍有活性）。DtHNL1-CLEA 用于两相体系中（R）-扁桃腈的合成（转化率 99%，对映体过量 98%），并在立即使非固定化 DtHNL1 失活的反应条件下用于（R）-羟基频哪醛氰醇的合成。结果表明，DtHNL1-CLEA 是在酸性条件下合成对映体纯氰醇的稳定生物催化剂。
