L-proline modified inactivated lipase and its immobilization on cellulose-based material: stability and enantioselectivity

BACKGROUND: Chemical modification is a simple, low cost, very fast and easy production that has no limits as to the nature of the groups introduced into the enzymes. Chemical modification may be directed to improve enzyme stability, as well as selectivity, specificity, and activity. RESULTS: Candida rugosa lipase (CRL) was immobilized onto a cellulose-based support. The native, inactivated, and immobilized lipases were modified by the reaction of L-proline (Prl) in the presence of coupling reagent (EDC). The catalytic properties of the modified lipases were evaluated by hydrolysis of p-nitrophenylpalmitate and the enantioselective hydrolysis of racemic naproxen methyl ester. It was observed that by chemical modification with proline, the hydrolytic activities of native, inactivated, and immobilized lipases increased 2.4, 11.0, and 2.2-fold, respectively. The immobilized lipase retained 64% of its activity after 120 min at 60 °C, while immobilized L-proline modified lipase was found to retain 72%. It was also found that the immobilized inactivated lipase kept 44% of its activity at 60 °C for 2 h, while the immobilized L-proline modified inactivated lipase retained their activity at 65%. In addition, the attained results of the best enantioselectivity of CRL-Prl exhibited a 2.2-fold improvement compared to the native enzyme. CONCLUSION: The method is simple, cost-effective, very fast, and it can obtain stronger biocatalysts. It was understood that a lipase lost its activity and could be reused after being simply modified with L-proline. This study predicts that such facile chemical modifications will open new avenues to develop industrially important biocatalyst with superior catalytic properties. © 2021 Society of Chemical Industry (SCI).