Godase_2023_Process.Biochem_125_248

Microbial epoxide hydrolases (EHs) find relevance in the pharmaceutical and biotechnology industries. The gene (YALI0_A01441g) encoding an epoxide hydrolase (Yleh) from a tropical marine yeast Yarrowia lipolytica NCIM 3589 was characterized. In-silico analysis suggested that the Yleh gene belonged to alpha/beta-hydrolase fold superfamily with two characteristic motifs, HGFP and GYTRS. Phylogenetic analysis showed that Yleh was far removed from microbial EHs. The cloned, expressed protein was a 42 kDa enzyme exhibiting EH activity of 4.07 +/-2.19 micromol min mg-1 protein with 1,2-epoxyhexane. It was active over a wide range of temperature (20-50 C) and pH (4-10) with optimal activity at 30 C and pH 8.0. For 1,2-epoxyhexane, Km, Vmax and kcat/Km values were 2.14 +/- 0.25 mM, 0.025 +/- 0.002 micromol min-1 and 8.48 +/- 1.71 mM-1 s-1 respectively. EH activity was strongly inhibited by Ag2+, Hg2+, Zn2+, whereas Cu3+ and Cu2+ enhanced it. Ligand binding studies indicated a good affinity (Ka=0.036 mM) between substrate and Yleh. Studies with purified enzyme and permeabilized cells on 1,2-epoxyhexane (2.5-15 mM) suggest specificity towards (R)-1,2-epoxyhexane with the production of (R)-1,2-hexanediol with -70 % and 80 % conversion, respectively. Thus, Yleh from Y. lipolytica might serve as a promising candidate to meet the process for conversion of epoxides to industrially relevant diols