Advantage of leaky expression, acid solubilization and CHAPS in the production of cost-effective bone morphogenetic...

The aim of this study was to purify BMP-2 in an easy and time-efficient way. We have developed a new method in which BMP-2 is produced through leaky expression in E. coli BL21 (DE3) cells as inclusion bodies, eliminating the need for inducer Isopropyl β-D-1-thiogalactopyranoside (IPTG). Inclusion bodies were solubilized by the acid denaturation method. Several refolding agents, along with a reducing and oxidizing environment, were tried to produce a correctly folded dimer, which is the biologically active form of BMP-2. CHAPS was found to be the most effective refolding agent at a concentration of 20 mM. The activity of the purified protein was confirmed by alkaline phosphatase assay and calcium deposition assay on C2C12 cells and native PAGE analysis was done to check binary complex formation upon binding between BMP-2 and ALK-3 receptor. These results demonstrate that the synthesized BMP-2 protein is biologically active and has potential clinical applications.