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Expression, Purification, Crystallization, and Enzyme Assays of Fumarylacetoacetate Hydrolase Domain-Containing Proteins
Published on: June 20, 2019
A Comparative Biochemical Study of Oleate Hydratases
Maxim van Delft1, Alejandro Gran-Scheuch1, Ulf Hanefeld1
1Department of Biotechnology, Delft University of Technology, Delft, The Netherlands.
Chembiochem : a European Journal of Chemical Biology
|July 30, 2026
Summary
Oleate hydratases (Ohys) are biocatalysts converting oleic acid to hydroxy fatty acids. This study compared four Ohys, finding EmOhy most thermostable and effective for high yields of 10-hydroxystearic acid.
Area of Science:
- Biocatalysis
- Enzyme Engineering
- Renewable Feedstock Valorization
Background:
- Oleate hydratases (Ohys) efficiently convert oleic acid to hydroxy fatty acids using water.
- Direct comparison of Ohys is challenging due to varied assay methods.
- Four Ohys from different homologous families (HFams) were selected for characterization.
Purpose of the Study:
- To characterize and comparatively analyze four distinct oleate hydratases.
- To assess enzyme expression, cofactor requirements, and catalytic performance.
- To evaluate thermostability and identify optimal conditions for 10-hydroxystearic acid production.
Main Methods:
- Expression of four Ohys (EmOhy, SnOhy, ReOhy, RpOhy) in Escherichia coli.
- Determination of FAD occupancy and cofactor supplementation effects (FADH2).
- Enzyme activity assays, thermal shift assays for thermostability analysis.
Main Results:
- High expression yields achieved for all enzymes, particularly SnOhy.
- FAD cofactor status impacted activity; FADH2 supplementation significantly enhanced yields (up to 12-fold).
- EmOhy demonstrated superior 10-hydroxystearic acid yields at higher substrate loading and longer reaction times, alongside highest thermostability (Tm = 54°C).
Conclusions:
- Comparative analysis revealed significant differences in Ohy performance and cofactor dependency.
- EmOhy is a promising candidate for industrial applications requiring thermostable oleate hydratase activity.
- Optimized cofactor status and reaction conditions are crucial for maximizing Ohy biocatalytic efficiency.
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