[Enhancing hRANKL production in Escherichia coli by optimizing culture conditions and lysing program]

RANKL/RANK/OPG axis is important in bone metabolism regulation, and becomes a popular research area in bone diseases. RANKL is a critical part of RANKL/RANK/OPG axis, and widely required in bone metabolism research. However, the yield of recombinant soluble human RANKL (hRANKL) in Escherichia coli is much lower than mouse RANKL (mRANKL). In this study, by adjusting and stabilizing the pH value of LB medium at 7.5, lowering the inducing temperature to 16 ℃ and optimizing the lysis program, the yield of soluble hRANKL increased by approximately 5 to 12-fold over the non-adjusted group. Our experiment effectively enhanced soluble hRANKL expression in E. coli and might constitute a meaningful attempt to obtain soluble expression of recombinant protein in E. coli.