Characterization of a novel amine transaminase from Halomonas elongata

Abstract

Chiral amines are indispensable building blocks in the production of biologically active compounds. They are fundamental for the pharmaceutical industry, both as active molecules themselves and as chiral auxiliaries in asymmetric synthesis; however, the available synthetic strategies often present disadvantages. ω-Transaminases (ω-TAs) appear as an attractive alternative by driving the stereoselective amination of prochiral ketones. HEWT is a novel amine transaminase from the moderate halophilic bacterium, Halomonas elongata DSM 2581, which is highly (S)-selective, being able to fully convert (S)-1-phenylethylamine to acetophenone and showing no activity with the corresponding (R)-1-phenylethylamine. HEWT has a broad substrate scope, active with a range of amino donors and acceptors, and naturally accepts isopropylamine (IPA) as amino donor in asymmetric synthesis providing a 41% conversion of pyruvate in 24 h at 37 °C starting with 1:1 molar ratio between the reagents. HEWT also accepts ortho-xylylenediamine as amino donor in for amine synthesis, in particular, with benzaldehyde yielding high conversions between 90 and 95%. The enzyme is also tolerant to the presence of cosolvents up to 20% making it a promising candidate for industrial applications

Highly Efficient Oxidation of Amines to Aldehydes with Flow‐based Biocatalysis

“…Protein expression and purification was performed following previously reported protocols in Cerioli et al. ; immobilisation was conducted according to the procedure reported by Planchestainer et al …”

“…In this context, we developed an efficient bio‐preparation of nature‐identical flavours and fragrances exploiting the immobilised amine transaminase from the moderate halophilic bacterium Halomonas elongata (HEWT), which is able to tolerate a range of temperature, pH, salts and co‐solvents in a continuous flow reactor. The combination of biocatalysis and flow reactor technology can be considered as an enabling methodology intrinsically compatible with the principles of green chemistry .…”

Enantioselective biotransformation of sterically hindered amine substrates by the fungus Stemphylium lycopersici

“…The same strategy of asymmetric synthesis was applied by Cerioli et al . () in order to infer the stereopreference to a novel amine transaminase from the bacterium Halomonas elongata DSM. They assigned this strain as highly (S)‐selective based on their ability to fully convert ( S )‐1‐phenylethylamine to acetophenone and showed no detectable activity with the opposite enantiomer.…”

Genetically Fused T4L Acts as a Shield in Covalent Enzyme Immobilisation Enhancing the Rescued Activity

“…Expression, Purification, and Characterization of the HEWT, BS2m, HLADH, and T4L Proteins in E. coli Protein expression, purification, characterization of the original HEWT, BS2m, and HLADH, and their T4L constructs was performed following previously reported protocols [17,20,21]. The assay for the BS2m esterase (and NovoZyme 435) was adapted using the para-nitrophenyl acetate (PNPA) as standard substrate.…”