Effects of Gln102Arg and Cys97Gly mutations on the structural specificity and stereospecificity of the L-lactate dehydrogenase from Bacillus stearothermophilus
作者:Helmut K. W. Kallwass、Marcel A. Luyten、Wendy Parris、Marvin Gold、Cyril M. Kay、J. Bryan Jones
DOI:10.1021/ja00038a016
日期:1992.6
The L-lactatedehydrogenase of Bacillusstearothermophilus (BSLDH) is a thermostable enzyme with considerable potential for applications in asymmetric synthesis. An understanding of the factors controlling its structural specificity and stereospecificity is therefore of interest. In this paper the effects of GIn 102→Arg and Cys97→Gly mutations have been evaluated. In a survey of thirteen 2-keto acids
Converging conversion – using promiscuous biocatalysts for the cell-free synthesis of chemicals from heterogeneous biomass
作者:Samuel Sutiono、André Pick、Volker Sieber
DOI:10.1039/d0gc04288a
日期:——
and 2-KG production from D-xylose and L-arabinose. Simple optimization and reaction engineering allowed us to obtain BDO and 2-KG titers of 18 g L−1 and 42 g L−1, with theoretical yields of >75% and >99%, respectively. One of the promiscuous enzymes identified together with auxiliary promiscuous enzymes was also suitable for stereoconvergent synthesis from a mixture of D-glucose and D-galactose, predominant
已经提出了由木质纤维素生物质生产化学品的替代品。然而,生物质利用的一个固有挑战是底物的异质性,导致水解后存在混合糖。混合糖的发酵通常导致差的产量和多种副产物的产生,因此使随后的下游加工复杂化。因此,近年来已经开发了系统生物催化来应对这一挑战。在这项工作中,使用基于序列的发现方法,鉴定了几种具有广泛底物混杂的新型酶,这些酶是D-木糖和L转化的合适生物催化剂。-阿拉伯糖,植物生物量中半纤维素的两个主要成分。这些混杂酶使得D-木糖和L-阿拉伯糖能够同时进行生物转化,从而以最大的3 g L -1 h -1的产率和> 95%的产率产生1,4-丁二醇(BDO)。使用O 2作为辅因子循环的辅助底物,该模型系统进一步适应于由戊糖生产α-酮戊二酸(2-KG)的最大生产率,达到4.2 g L -1 h -1和99%的产率。为了验证我们系统的潜在适用性,我们尝试扩大D-木糖和L的BDO和2-KG产量-阿拉伯糖。
An Enzymatic N‐Acylation Step Enables the Biocatalytic Synthesis of Unnatural Sialosides
material for many biotechnological products through manipulation of its N-acetyl functionality, which can be cleaved under mild conditions using the enzyme family of de-N-acetylases. However, the chemoselective enzymatic re-acylation of glucosaminederivatives, which can introduce new stable functionalities into chitin derivatives, is much less explored. Herein we describe an acylase (CmCDA from Cyclobacterium
Repurposing an Aldolase for the Chemoenzymatic Synthesis of Substituted Quinolines
作者:Douglas J. Fansher、Richard Granger、Satinderpal Kaur、David R. J. Palmer
DOI:10.1021/acscatal.1c01398
日期:2021.6.18
Quinoline derivatives are important natural products and pharmaceuticals, but their synthesis can be challenging due to poor yields, harsh reaction conditions, and instability of starting materials. Here we report the chemoenzymatic synthesis of quinaldic acids under mild conditions using an aldolase, trans-o-hydroxybenzylidenepyruvate hydratase-aldolase (NahE, or HBPA). A series of 2-aminobenzaldehydes
喹啉衍生物是重要的天然产物和药物,但由于收率低、反应条件苛刻和起始材料不稳定,它们的合成具有挑战性。在这里,我们报告了使用醛缩酶、反式-o-羟基亚苄基丙酮酸水合酶-醛缩酶(NahE 或 HBPA)在温和条件下化学酶法合成喹哪二酸。在 NahE 存在下,一系列源自相应硝基类似物还原的 2-氨基苯甲醛与丙酮酸反应,以高达 93% 的分离产率得到取代的喹啉。该反应不同于体内NahE 催化的羟醛缩合,而是类似于由其同源物二氢吡啶二羧酸合酶催化的杂环形成。
L-2-Hydroxyglutarate production arises from noncanonical enzyme function at acidic pH
作者:Andrew M Intlekofer、Bo Wang、Hui Liu、Hardik Shah、Carlos Carmona-Fontaine、Ariën S Rustenburg、Salah Salah、M R Gunner、John D Chodera、Justin R Cross、Craig B Thompson
DOI:10.1038/nchembio.2307
日期:2017.5
Acidification enhances lactate dehydrogenaseâ and malate dehydrogenaseâmediated promiscuous production of L-2-hydroxyglutarate (L-2HG) from α-ketoglutarate and stabilizes HIF-1α levels. The metabolite 2-hydroxyglutarate (2HG) can be produced as either a D- R- or L- S- enantiomer, each of which inhibits α-ketoglutarate (αKG)-dependent enzymes involved in diverse biologic processes. Oncogenic mutations in isocitrate dehydrogenase (IDH) produce D-2HG, which causes a pathologic blockade in cell differentiation. On the other hand, oxygen limitation leads to accumulation of L-2HG, which can facilitate physiologic adaptation to hypoxic stress in both normal and malignant cells. Here we demonstrate that purified lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) catalyze stereospecific production of L-2HG via 'promiscuous' reduction of the alternative substrate αKG. Acidic pH enhances production of L-2HG by promoting a protonated form of αKG that binds to a key residue in the substrate-binding pocket of LDHA. Acid-enhanced production of L-2HG leads to stabilization of hypoxia-inducible factor 1 alpha (HIF-1α) in normoxia. These findings offer insights into mechanisms whereby microenvironmental factors influence production of metabolites that alter cell fate and function.