Enhancement of Solubility, Purification, and Inclusion Body Refolding of Active Human Mitochondrial Aldehyde Dehydrogenase 2
Tingting Zhao, Hui Huang, Peizhu Tan, Yanze Li, Xiuchen Xuan, Fenglan Li, Yuchen Zhao, Yuwei Cao, Zhaojing Wu, Yu Jiang, Yuanyuan Zhao, Aimiao Yu, Kuo Wang, Jiaran Xu, Lingyun Zhou, Dan Yang
Abstract
Mitochondrial aldehyde dehydrogenase 2 (ALDH2) is predominantly linked with acetaldehyde detoxification in the second stage of alcohol metabolism. To intensively study ALDH2 function, a higher purity and uniform composition of the protein is required. An efficient Escherichia coli system for ALDH2 expression was developed by using His and a small ubiquitin-related modifier fusion tag. Most of the recombinant ALDH2s were expressed in the form of inclusion bodies. The ALDH2-enriched inclusion bodies were denatured with 6 M guanidine hydrochloride, and then ALDH2 was ultrafitrated. Finally, ALDH2 was successfully purified through affinity and gel filtration chromatography. The purified ALDH2 was finally preserved by the vacuum freeze-drying method, and its purity was determined to be higher than 95%, with a final media yield of 33.89 mg/L. The specific activity of ALDH2 was 6.1 × 104 U/mg. This work was the first to report pET-SUMO-ALDH2 recombinant plasmid expression in Escherichia coli, and the inclusion bodies were isolated and refolded. Finally, the purified ALDH2 had relatively higher purity, yield, and biological activity.