Aspergillus niger lipase: gene cloning, over-expression in Escherichia coli and in vitro refolding

From the N-terminal amino acid sequence of the lipase from Aspergillus niger F044, a potential homologous gene A84689 to the lipanl (the gene encoding the lipase from Aspergillus niger F044) was identified. A pair of primers were designed according to the nucleotide sequence of A84689, and the lipanl was cloned by PCR. Nucleotide sequencing revealed that the lipanl has an ORF of 1,044 bp, containing three introns. The deduced amino acid sequence corresponds to 297 amino acid residues. The cloned cDNA fragment encoding the mature lipase from Aspergillus niger F044 was over-expressed in Escherichia coli BL21(De3) and the recombinant protein was refolded in vitro by dilution followed by DEAE Sepharose Fast Flow chromatography.