Amination of Ketones by Employing Two New (S)‐Selective ω‐Transaminases and the His‐Tagged ω‐TA from Vibrio fluvialis

Abstract

AbstractTwo recently identified (S)‐selective ω‐transaminases (ω‐TAs) that originate from Paracoccus denitrificans (Strep‐PD‐ωTA, cloned with an N‐terminal Strep‐tag II) and Pseudomonas fluorescens (PF‐ωTA) were employed for the asymmetric amination of selected prochiral ketones. The substrates tested were transformed into optically pure amines (>99 % ee) with high conversion (up to >99 %). The ω‐TAs led to higher conversion in the absence of dimethyl sulfoxide as a cosolvent than in its presence (15 %, v/v). Additionally, it was shown that a His‐tagged recombinant transaminase from Vibrio fluvialis (His‐VF‐ωTA, cloned with an N‐terminal His6‐tag) showed for a single substrate, ethyl acetoacetate, significantly higher stereoselectivity for the amination compared to the corresponding commercial enzyme preparation (>99 vs. 50 %).