A reductive aminase from Aspergillus oryzae

• Published in: Nature chemistry 2017-10, Vol.9 (10), p.961-969
• Main Authors: Aleku, Godwin A., France, Scott P., Man, Henry, Mangas-Sanchez, Juan, Montgomery, Sarah L., Sharma, Mahima, Leipold, Friedemann, Hussain, Shahed, Grogan, Gideon, Turner, Nicholas J.
• Format: Article
• Language: English
• Subjects: 639/638/77/603; 639/638/92/603; Amination; Amines; Amines - metabolism; Amino acids; Aminohydrolases - chemistry; Aminohydrolases - genetics; Aminohydrolases - metabolism; Ammonia; Analytical Chemistry; Aspergillus oryzae; Aspergillus oryzae - enzymology; Biocatalysis; Biocatalysts; Biochemistry; Carbonyl compounds; Carbonyls; Chemistry; Chemistry/Food Science; Conversion; Coupling (molecular); Crystal structure; Dehydrogenases; Enzymes; Inorganic Chemistry; Models, Molecular; Molecular Structure; Mutation; NADP; Organic Chemistry; Oxidation-Reduction; Physical Chemistry; Rasagiline; Substrates
• ISSN: 1755-4330; 1755-4349
• DOI: 10.1038/nchem.2782

Reductive amination is one of the most important methods for the synthesis of chiral amines. Here we report the discovery of an NADP(H)-dependent reductive aminase from Aspergillus oryzae ( Asp RedAm, Uniprot code Q2TW47) that can catalyse the reductive coupling of a broad set of carbonyl compounds with a variety of primary and secondary amines with up to >98% conversion and with up to >98% enantiomeric excess. In cases where both carbonyl and amine show high reactivity, it is possible to employ a 1:1 ratio of the substrates, forming amine products with up to 94% conversion. Steady-state kinetic studies establish that the enzyme is capable of catalysing imine formation as well as reduction. Crystal structures of Asp RedAm in complex with NADP(H) and also with both NADP(H) and the pharmaceutical ingredient ( R )-rasagiline are reported. We also demonstrate preparative scale reductive aminations with wild-type and Q240A variant biocatalysts displaying total turnover numbers of up to 32,000 and space time yields up to 3.73 g l −1  d −1 . An enzyme ( Asp RedAm) capable of coupling carbonyls with a variety of amines in a reductive amination has now been discovered. Kinetic studies revealed that the enzyme catalysed both the imine formation step, as well as the reduction step. Structure and mutagenesis studies have highlighted essential catalytic residues and preparative scale examples have demonstrated total turnover numbers of up to 32,000.