Functional expression of porcine aminoacylase 1 in E. coli using a codon optimized synthetic gene and molecular chaperones

Abstract

Efficient recombinant expression of N-acyl-L-aminoacylase 1 from pig kidney (pAcy1) was achieved in the prokaryotic host Escherichia coli. An optimized nucleotide sequence (codon adaptation index 0.95 for E. coli), was cloned into vector pET-52(b) yielding an E. coli-expressible pAcy1 gene. Formation of inclusion bodies was alleviated by co-expression of molecular chaperones resulting in 2.7- and 4.2-fold increased recovery of active pAcy1 using trigger factor or GroEL-GroES, respectively. Facile purification was achieved via StrepTag affinity chromatography. Overall, more than 80 mg highly active pAcy1 (94 U/mg) was obtained per liter of cultivation broth. The protein was analyzed for structural and functional identity, and the performances of further described expression and purification systems for pAcy1 were compared.