Expression and characterization of a thermostable penicillin G acylase from an environmental metagenomic library

摘要

One clone (ACPGA001) exhibiting penicillin G acylase (PGA) activity was screened from a metagenomic library by using a medium containing penicillin G. A novel PGA gene from the inserted fragment of ACPGA001 was obtained by sequencing. The amino acid sequence of ACPGA001 PGA exhibited < 33 % similarity to PGAs retrieved from GenBank. This gene was expressed in Escherichia coli M15 and the recombinant protein was purified and characterized. The ACPGA001 PGA exhibited a maximum activity at 60 A degrees C and showed high activity at pH 4-10 with an optimum pH of 8.0. This enzyme was stable at 40 A degrees C for 70 min with a half-life of 60 min at 55 A degrees C. These beneficial characteristics of ACPGA001 PGA provide some advantages for the potential application of ACPGA001 PGA in industry.