Fig. 4. Effects of temperature (a), enzyme concentration (b), IPA equivalents (c) and substrate concentration (d) on yield of 18b using IPA 27 as an amine donor for pQR2189. General reaction conditions: Amine donor 27 (100 mM), amino acceptor (10 mM), PLP (1 mM), KPi buffer pH 8 (100 mM) and clarified cell extract (0.4 mg mL–1), 20% DMSO, 35 °C, 400 rpm, 18 h. Yields were determined using HPLC against product standards. All reactions were performed in triplicate, and standard deviations were <8%. Reaction condition variations: (a) Temperature 20–70 °C, (b) clarified cell lysate 0.04–4 mg mL–1, (c) 1–50 equivalents of IPA 27 and (d) 10–200 mM amino acceptor 18a.
