Modification of Porcine Pancreatic Lipase with Z‐Proline

Abstract

Porcine pancreatic lipase was modified with Z-proline via the constitution of amide bonds between the free amino groups of lipase and the carboxyl groups of Z-proline, which were activated by 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide (EDC). Different amounts of Z-proline were bound to lipase. Modification degree was determined by 2,4,6-trinitrobenzene sulphonic acid (TNBS), by means of the decrease in free amino groups on lipase. The reason for choosing Z-proline was its unique structural characteristics, protected amino groups, and its effect on protein conformation by reducing the flexibility of the lipase molecule, thus achieving stabilization against changes in pH and temperature. After the modification, porcine pancreatic lipase was found to have new physicochemical characteristics, such as optimum alkaline pH stability and thermal stability at elevated temperatures.

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

“…In the modified lipase, an increase in the hydrophobic aggregation on its surface is predicted, and the decrease in positive charge due to the exchange of lysine residue with the uncharged hydrophobic group can alter the modified lipase's elasticity and lipase compatibility. 15,50 The modified inactivated lipase-Prl showed 1.34 U mL −1 , while inactivated lipase was 0.12 U mL −1 . Further, after chemical modification of lipase with proline, it exhibited approximately 2.3-and 11-fold enhancement in the activities of native and inactivated enzymes, respectively.…”

“…The native CRL was found to give 1.43 U mL −1 , while CRL‐Prl was 3.4 U mL −1 . In the modified lipase, an increase in the hydrophobic aggregation on its surface is predicted, and the decrease in positive charge due to the exchange of lysine residue with the uncharged hydrophobic group can alter the modified lipase's elasticity and lipase compatibility 15,50 . The modified inactivated lipase–Prl showed 1.34 U mL −1 , while inactivated lipase was 0.12 U mL −1 .…”

“…It was observed that the immobilized inactivated lipase loses 56% of its activity within around 120 min at 60 °C, while immobilized inactivated‐CRL‐Prl retains its activities at about 65%. Proline provides protection for the structural integrity of the enzyme, thus maintaining its activity 15,29,56 …”

“…Proline provides protection for the structural integrity of the enzyme, thus maintaining its activity. 15,29,56 Enantioselectivity assay Native, inactivated, immobilized, and modified lipases have been used in the hydrolysis of the racemic naproxen methyl ester (Fig. 5).…”

“…11,12 Especially with specific modifications, the efficiency of native biocatalysts can be increased and new properties can be obtained for enzymes. This traditional method is a simple, low cost, very fast and easy production [13][14][15][16][17] that has no limits as to the nature of the groups introduced into the enzymes. Therefore, several physical and chemical methods, along with protein engineering (such as immobilization, modification, and entrapment for stabilizing enzymes), have been developed.…”