327-57-1Relevant articles and documents
Enantioselective biocatalytic formal α-amination of hexanoic acid to l-norleucine
Dennig, Alexander,Gandomkar, Somayyeh,Cigan, Emmanuel,Reiter, Tamara C.,Haas, Thomas,Hall, Mélanie,Faber, Kurt
, p. 8030 - 8033 (2018)
A three-step one-pot biocatalytic cascade was designed for the enantioselective formal α-amination of hexanoic acid to l-norleucine. Regioselective hydroxylation by P450CLA peroxygenase to 2-hydroxyhexanoic acid was followed by oxidation to the ketoacid by two stereocomplementary dehydrogenases. Combination with final stereoselective reductive amination by amino acid dehydrogenase furnished l-norleucine in >97% ee.
2(S)-Aminohex-5-ynoic acid, an antimetabolite from Cortinarius claricolor var. Tenuipes
Aoyagi, Yasuo,Sugahara, Tatsuyuki
, p. 1835 - 1836 (1985)
Screening for antimetabolites in edible mushrooms showed that the hot water extract of fruiting bodies of Cortinarius claricolor var. tenuipes strongly inhibited the growth of Bacillus subtilis B-50 in a chemically defined minimal medium. 2(S)-Aminohex-5-ynoic acid was isolated as an active compound.
Bioelectrocatalytic Conversion from N2 to Chiral Amino Acids in a H2/α-Keto Acid Enzymatic Fuel Cell
Cai, Rong,Chen, Hsiaonung,Chen, Hui,Dong, Fangyuan,Minteer, Shelley D.,Prater, Matthew B.
supporting information, p. 4028 - 4036 (2020/03/11)
Enzymatic electrosynthesis is a promising approach to produce useful chemicals with the requirement of external electrical energy input. Enzymatic fuel cells (EFCs) are devices to convert chemical energy to electrical energy via the oxidation of fuel at the anode and usually the reduction of oxygen or peroxide at the cathode. The integration of enzymatic electrosynthesis with EFC architectures can simultaneously result in self-powered enzymatic electrosynthesis with more valuable usage of electrons to produce high-value-added chemicals. In this study, a H2/α-keto acid EFC was developed for the conversion from chemically inert nitrogen gas to chiral amino acids, powered by H2 oxidation. A highly efficient cathodic reaction cascade was first designed and constructed. Powered by an applied voltage, the cathode supplied enough reducing equivalents to support the NH3 production and NADH recycling catalyzed by nitrogenase and diaphorase. The produced NH3 and NADH were reacted in situ with leucine dehydrogenase (LeuDH) to generate l-norleucine with 2-ketohexanoic acid as the NH3 acceptor. A 92% NH3 conversion ratio and 87.1% Faradaic efficiency were achieved. On this basis, a H2-powered fuel cell with hyper-thermostable hydrogenase (SHI) as the anodic catalyst was combined with the cathodic reaction cascade to form the H2/α-keto acid EFC. After 10 h of reaction, the concentration of l-norleucine achieved 0.36 mM with >99% enantiomeric excess and 82% Faradaic efficiency. From the broad substrate scope and the high enzymatic enantioselectivity of LeuDH, the H2/α-keto acid EFC is an energy-efficient alternative to electrochemically produce chiral amino acids for biotechnology applications.
Combinatorial Mutation Analysis of ω-Transaminase to Create an Engineered Variant Capable of Asymmetric Amination of Isobutyrophenone
Kim, Hong-Gon,Han, Sang-Woo,Shin, Jong-Shik
, p. 2594 - 2606 (2019/05/15)
ω-Transaminase (ω-TA) is an important enzyme for asymmetric synthesis of chiral amines. Rapid creation of a desirable ω-TA variant, readily available for scalable process operation, is demanded and has attracted intense research efforts. In this study, we aimed to develop a quantitative mutational analysis (i. e., R-analysis) that enables prediction of combinatorial mutation outcomes and thereby provides reliable guidance of enzyme engineering through combination of already characterized mutations. To this end, we determined three mutatable active-site residues of ω-TA from Ochrobactrum anthropi (i. e., leucine 57, tryptophan 58 and valine 154) by examining activities of nine alanine-scanning mutants for seven substrate pairs. The R-analysis of the mutatable residues is based on assessment of changes in relative activities for a series of structurally analogous substrates. Using three sets of substrates (five α-keto acids, six arylalkylamines and three arylalkyl ketones), we found that combination of two point mutations display additive effects of each mutational outcome such as steric relaxation for bulky substrates or catalytic enhancement for amination of ketones. Consistent with the R-analysis-based prediction, the ω-TA variant harboring triple alanine mutations, i. e. L57A, W58A and V154A, showed high activity improvements for bulky substrates, e. g. a 3.2×104-fold activity increase for 1-phenylbutylamine. The triple mutant even enabled asymmetric amination of isobutyrophenone, carrying a branched-chain alkyl substituent to be accepted in a small binding pocket that normally shows a steric limit up to an ethyl group, with >99% ee of a resulting (S)-amine. (Figure presented.).
