Purification and biochemical characterization of a novel ene- reductase from Kazachstania exigua HSC6 for dihydro-β-ionone from β-ionone

Abstract

Purpose: We purified and characterized a novel ene-reductase (KaDBR1) from Kazachstania exigua HSC6 for the synthesis of dihydro-β-ionone from β-ionone.

Methods: KaDBR1 was purified to homogeneity by ammonium sulfate precipitation and phenyl-Sepharose Fast Flow and Q-Sepharose chromatography. The purified enzyme was characterized by measuring the amount of dihydro-β-ionone from β-ionone with LC-MS analysis method.

Results: The molecular mass of KaDBR1 was estimated to be 45 kDa by SDS-PAGE. The purified KaDBR1 enzyme had optimal activity at 60 °C and pH 6.0. The addition of 5 mM Mg²⁺, Ca²⁺, Al³⁺, Na⁺, and dithiothreitol increased the activity of KaDBR1 by 25%, 18%, 34%, 20%, and 23%, respectively. KaDBR1 favored NADH over NADPH as a cofactor, and its catalytic efficiency (kcat/Km) toward β-ionone using NADH was 8.1-fold greater than when using NADPH.

Conclusion: Owing to its unique properties, KaDBR1 is a potential candidate for the enzymatic biotransformation of β-ionone to dihydro-β-ionone in biotechnology applications.

Keywords: Dihydro-β-ionone; Ene-reductase purification; Kazachstania exigua HSC6; β-Ionone.