Expression of heme oxygenase-1 in gene recombinant Escherichia coli and optimization of its cultivation

Abstract:

[Background] Heme oxygenase-1 (HO-1) has many physiological effects, such as anti-oxidative stress, anti-apoptosis and anti-fibrosis, and is expected to become a new drug for the treatment of clinical diseases. [Objective] A gene recombinant Escherichia coli was constructed for expressing HO-1, and its culture conditions were optimized to achieve the high yield of HO-1. [Methods] The gene of HO-1 (ho1) was cloned from the cell of Synechocystis sp. PCC 6803, and was recombined with the plasmid of pET-28a. The recombinant plasmid (pET-28a-ho1) was transformed into E. coli BL21(DE3). The single factor experiment was applied to optimize the type of medium, inducer adding time, cultivation time, inducer concentration and cultivation temperature for the expression of HO-1. [Results] A gene recombinant E. coli strain, BL21(DE3)/pET-28a-ho1, was successfully constructed for expressing HO-1. When the strain was cultured in glycerol medium (GY), and as the cell OD600 was about 0.8, IPTG with the final concentration of 0.1 mmol/L was added, the highest yield of HO-1 could be obtained after induction cultivation for 6 h at 30 °C. Separation of HO-1 by Ni-NTA column accounted for 10.9% yield of the total cell protein. [Conclusion] A gene recombinant E. coli strain, and its optimal cultivation conditions were achieved for the expression of soluble HO-1, which laid a foundation for further study on the enzymatic properties and application of HO-1 from Synechocystis sp.

Key words:Heme oxygenase, Prokaryotic expression, Escherichia coli, Optimization of cultivation