Immobilization of lipase on aminopropyl-grafted mesoporous silica nanotubes for the resolution of (R, S)-1-phenylethanol

Mesoporous silica nanotubes and aminopropyl-grafted mesoporous silica nanotubes were prepared as supports to immobilize lipase from Candida sp. 99-125(ClLip) by physical adsorption. The immobilization conditions were investigated. Moreover, immobilized lipases on both kinds of supports were employed to catalyze olive oil hydrolization and resolution of 1-phenylethanol by esterification. The results showed that the hydrolization activity of the lipase immobilized on aminopropyl-grafted mesoporous silica nanotubes was almost twice of that on mesoporous silica nanotubes. In addition, the resolution of 1-phenylethanol catalyzed by the former catalyst also increased 22%. Circular dichroism spectra revealed a reduction of α-helix and an increase of β-sheet when lipase was adsorbed on aminopropyl-grafted mesoporous silica nanotubes, which suggested that parts of α-helix were extended and reformed to be β-sheet.

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► Two silica nanotubes were prepared as carriers to immobilize lipase physically.
► These two carriers and the subsequent immobilized lipases were compared.
► Aminopropyl-modification of the carrier doubled the activity of immobilized lipase.
► The resolution of 1-phenylethanol catalyzed by NH2-MSNTs-lipase achieved 22% more.
► Circular dichroism spectra showed structure changes of lipase after immobilization.