Recent progress in directed evolution of stereoselective monoamine oxidases

Enzymatic Routes for Chiral Amine Synthesis: Protein Engineering and Process Optimization

Chiral amines are essential motifs in pharmaceuticals, agrochemicals, and specialty chemicals. While traditional chemical routes to chiral amines often lack stereoselectivity and require harsh conditions, biocatalytic methods using engineered enzymes can offer high efficiency and selectivity under sustainable conditions. This review discusses recent advances in protein engineering of transaminases, oxidases, and other enzymes to improve catalytic performance. Strategies such as directed evolution, immobilization, and computational redesign have expanded substrate scope and enhanced efficiency. Furthermore, process optimization guided by techno-economic assessments has been crucial for establishing viable biomanufacturing routes. Combining state-of-the-art enzyme engineering with multifaceted process development will enable scalable, economical enzymatic synthesis of diverse chiral amine targets.

Novel Enzymatic Method for Imine Synthesis via the Oxidation of Primary Amines Using D-Amino Acid Oxidase from Porcine Kidney

During studies on the oxidative cyanation reaction catalyzed by a variant of D-amino acid oxidase from porcine kidney (pkDAO) (Y228L/R283G), an unexpected formation of 1-phenyl-N-(1-phenylethylidene)ethanamine (PPEA) was detected. The optimal reaction conditions for the synthesis of PPEA and the reaction mechanism were investigated using the pkDAO variant. The highest PPEA synthesis was obtained in the reaction with 150 mM (R)-MBA at pH 9.0 and at 20 °C. Since PPEA synthesis proceeded by trapping the intermediate 1-phenylethanimine (1-PEI) by 15N-labeled n-hexylamine, which is not a substrate for the pKDAO variant, it was deduced that PPEA would be synthesized by a nucleophilic substitution of 1-PEI by another molecule of (R)-MBA. PPEA was further identified by its conversion to bis(1-phenylethyl)amine (BPEA) through reduction with NaBH4. Thus, a new enzymatic method of imine synthesis by oxidation of primary amine by the variant pkDAO was achieved for the first time.

The role of biocatalysis in the asymmetric synthesis of alkaloids - an update

Alkaloids are a group of natural products with interesting pharmacological properties and a long history of medicinal application. Their complex molecular structures have fascinated chemists for decades, and their total synthesis still poses a considerable challenge. In a previous review, we have illustrated how biocatalysis can make valuable contributions to the asymmetric synthesis of alkaloids. The chemo-enzymatic strategies discussed therein have been further explored and improved in recent years, and advances in amine biocatalysis have vastly expanded the opportunities for incorporating enzymes into synthetic routes towards these important natural products. The present review summarises modern developments in chemo-enzymatic alkaloid synthesis since 2013, in which the biocatalytic transformations continue to take an increasingly 'central' role.

Recent trends in biocatalysis

Biocatalysis has undergone revolutionary progress in the past century. Benefited by the integration of multidisciplinary technologies, natural enzymatic reactions are constantly being explored. Protein engineering gives birth to robust biocatalysts that are widely used in industrial production. These research achievements have gradually constructed a network containing natural enzymatic synthesis pathways and artificially designed enzymatic cascades. Nowadays, the development of artificial intelligence, automation, and ultra-high-throughput technology provides infinite possibilities for the discovery of novel enzymes, enzymatic mechanisms and enzymatic cascades, and gradually complements the lack of remaining key steps in the pathway design of enzymatic total synthesis. Therefore, the research of biocatalysis is gradually moving towards the era of novel technology integration, intelligent manufacturing and enzymatic total synthesis.

Engineering Fatty Acid Photodecarboxylase to Enable Highly Selective Decarboxylation of trans Fatty Acids

Due to the high risk of heart disease caused by the intake of trans fatty acids, a method to eliminate trans fatty acids from foods has become a critical issue. Herein, we engineered fatty acid photo-decarboxylase from Chlorella variabilis (CvFAP) to selectively catalyze the decarboxylation of trans fatty acids to yield readily-removed hydrocarbons and carbon dioxide, while cis fatty acids remained unchanged. An efficient protein engineering based on FRISM strategy was implemented to intensify the electronic interaction between the residues and the double bond of the substrate that stabilized the binding of elaidic acid in the channel. For the model compounds, oleic acid and elaidic acid, the best mutant, V453E, showed a one-thousand-fold improvement in the trans-over-cis (ToC) selectivity compared with wild type (WT). As the first report of the direct biocatalytic decarboxylation resolution of trans/cis fatty acids, this work offers a safe, facile, and eco-friendly process to eliminate trans fatty acids from edible oils.