Imprinted cross-linked enzyme aggregate (iCLEA) of phenylalanine ammonia lyase: A new stable biocatalyst

Abstract

The industrial use of phenylalanine ammonia lyase (PAL), an interesting biocatalyst for manufacture of L-phenylalanine (L-Phe) by reversing the enzyme reaction with high concentration of trans-cinnamic acids (t-CA) and ammonia, has been hampered by a lack of long-term stability and low activity toward substrates. In this study, it is shown that the PAL activity of such a CLEA can be improved by molecular imprinting with a suitable substrate. PAL was imprinted with t-CA and subsequently cross-linked with glutaraldehyde (iCLEAs). Compared to free PAL, PAL stability in the iCLEAs against substrate inhibition was significantly improved, furthermore, the iCLEAs exhibited good reusability. These results indicated that the procedure might be used as a feasible and efficient solution for improving properties of immobilized enzyme in industrial application.