Different Properties of the Lipases Contained in Porcine Pancreatic Lipase Extracts as Enantioselective Biocatalysts

The porcine pancreatic lipase (PPL) extracts contain a mixture of several lipases. Their fractioning was performed by sequential adsorption via interfacial activation on supports with different hydrophobicity. A protein of 25 KDa was preferentially adsorbed on octyl -Sepharose, another protein of 33 kDa was mainly adsorbed on octadecyl-Sepabeads support, and the PPL was mainly adsorbed on the support bearing phenyl groups. The different immobilized preparations showed different properties and different response due to change in the experimental conditions. Thus, in the hydrolysis of (plus_minus)-2-hydroxy-4-phenylbutyric acid ethyl ester [(plus_minus)1] to produce the corresponding acid [2], the octyl-25KDa preparation showed the best enantioselectivity (E) value (E = 7) at pH 5 and 25 °C, whereas the phenyl-PPL was the most enantioselective (E = 10) at pH 5, 4 °C, and 10% dioxane. Using different preparations at different pHs it was possible to resolve (plus_minus)-2-O-butyryl-2-phenylacetic acid [(plus_minus)-3] with a high E value (E > 100); for example, with octadecyl-33 KDa enzyme at pH 8.