Leipold Leona, Dobrijevic Dragana, Jeffries Jack W E, Bawn Maria, Moody Thomas S, Ward John M, Hailes Helen C
Department of Chemistry , University College London , 20 Gordon Street , London WC1H 0AJ , UK . Email:
The Advanced Centre for Biochemical Engineering , Department of Biochemical Engineering , University College London , Bernard Katz Building , Gower Street , London WC1E 6BT , UK . Email:
Green Chem. 2019 Jan 7;21(1):75-86. doi: 10.1039/c8gc02986e. Epub 2018 Nov 15.
Transaminases remain one of the most promising biocatalysts for use in chiral amine synthesis, however their industrial implementation has been hampered by their general instability towards, for example, high amine donor concentrations and organic solvent content. Herein we describe the identification, cloning and screening of 29 novel transaminases from a household drain metagenome. The most promising enzymes were fully characterised and the effects of pH, temperature, amine donor concentration and co-solvent determined. Several enzymes demonstrated good substrate tolerance as well as an unprecedented robustness for a wild-type transaminase. One enzyme in particular readily accepted IPA as an amine donor giving the same conversion with 2-50 equivalents, as well as being tolerant to a number of co-solvents, and operational in up to 50% DMSO - a characteristic as yet unobserved in a wild-type transaminase. This work highlights the value of using metagenomics for biocatalyst discovery from niche environments, and here has led to the identification of one of the most robust native transaminases described to date, with respect to IPA and DMSO tolerance.
转氨酶仍然是用于手性胺合成的最具前景的生物催化剂之一，然而，它们的工业应用受到其对例如高胺供体浓度和有机溶剂含量普遍不稳定的阻碍。在此，我们描述了从家庭排水宏基因组中鉴定、克隆和筛选29种新型转氨酶的过程。对最具前景的酶进行了全面表征，并确定了pH、温度、胺供体浓度和共溶剂的影响。几种酶表现出良好的底物耐受性以及野生型转氨酶前所未有的稳健性。特别是有一种酶很容易接受异丙醇作为胺供体，在2 - 50当量时具有相同的转化率，并且耐受多种共溶剂，可在高达50%的二甲基亚砜中使用——这是野生型转氨酶尚未观察到的特性。这项工作突出了利用宏基因组学从特殊环境中发现生物催化剂的价值，在此已鉴定出迄今为止描述的对异丙醇和二甲基亚砜耐受性最强的天然转氨酶之一。
