Enhanced stability and reusability of marine epoxide hydrolase using ship-in-a-bottle approach with magnetically-separable mesoporous silica

We developed magnetically-separable and highly-stable biocatalyst system of Mugil cephalus epoxide hydrolase (McEH) for enantioselective hydrolysis of racemic epoxides. McEH protein was adsorbed and cross-linked into mesoporous silica with bottle-neck mesopores, which effectively prevented the leaching of cross-linked McEH in a larger mesocellular pores. This ship-in-a-bottle approach allows for highly loaded and stable McEH system. For example, free McEH showed only 7.5% of initial activity under shaking condition at 80 h while ship-in-a-bottled McEH retained 79.5% of initial activity in the same condition. Stable McEH in magnetically-separable mesoporous silica could achieve the yield of 45% for the preparation of enantiopure (S)-styrene oxide with 98%ee. The magnetic nanoparticles pre-incorporated in mesoporous silica enabled an easy recovery of immobilized McEH for repetitive batch resolutions of racemic styrene oxide, allowing for more than 50% of the initial activity was retained after seven recycled uses.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Magnetically-separable mesoporous silica was used to develop highly stable and magnetically-separable Mugil cephalus epoxide hydrolase (McEH) biocatalyst system. ► Nanoscale enzyme reactors of McEH (NER-McEH) effectively stabilized the activity of McEH. ► NER-McEH was used for enantioselective resolution of racemic styrene oxide under iterative recycles of enzymatic reaction and magnetic separation. ► Enantiopure (S)-styrene oxide with 98%ee was obtained by using the NER-McEH.