Bijan Soleymani - Medical Biology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran.
Ali Mostafaie - Medical Biology Research Center, Health Technology Institute, Kermanshah University of Medical Sciences, Kermanshah, Iran.

Background: Inclusion body formation in E. coli is a significant problem in recombinant protein production. The aim of this study was to improve the solubility of recombinant bovine sex determining region Y protein (SRY) in BL21 (DE3) E. coli cells. Methods: In this research two recombinant bovine SRY (rbSRY) sequences were analyzed; these were wild-type SRY (wtbSRY) and codon-optimized SRY (cobSRY). Their expression in various culture conditions was examined; these differences included IPTG concentrations, temperatures, and media stabilizers. Results: IPTG and temperature significantly affected rbSRY solubility (P < 0.001). The optimum IPTG concentration and temperatures for wtbSRY and cobSRY induction were 0.3 mM at 27 and 32 °C, respectively. In addition, arginine and sorbitol concentrations significantly affected rbSRY solubility (P < 0.01). Solubility of rbSRY protein was highest from the cobSRY construct in the presence 0.2 M arginine and 0.3 M sorbitol. The highest inclusion body production occurred with high glucose concentrations. Conclusions: We found that modifications in temperature and IPTG and stabilizer concentrations affected rbSRY solubility.  

Cobsry, Inclusion Bodies, Recombinant Bovine SRY Protein, Solubility, Wtbsry.