High-level expression and purification of recombinant human catalase in Pichia pastoris

Catalase is one of the antioxidant enzymes and is involved in many pathophysiologic processes and human diseases. This study focused on high-level expression and purification of recombinant catalase in Pichia pastoris. The cDNA encoding catalase was cloned by RT-PCR from Fetal liver of Homo sapiens. After PCR and construction of expression vector pPIC9K-CAT, human catalase was expressed highly in P. pastoris yeast SMD1168 and secreted into the culture medium. The secreted catalase was purified to a purity of 95% by ammonium sulfate fractionation, anionic exchange-chromatography, and Macro-prep Ceramic Hydroxyapatite with a overall yield of 60%. This study provides a new method for large-scale expression and purification of recombinant protein catalase.