Aim: To obtain recombinant rat betacellulin with biological activity.
Methods: A 534 bp of rat betacellulin gene fragment was amplified by RT-PCR from rat kidney and cloned into pET28a(+) vector to construct recombinant plasmid pET28a-rBTC. The recombinant plasmid was transformed into E. coli BL-21(DE3) and the betacellulin was expressed under IPTG induction. The expressed betacellulin was detected by SDS-PAGE and Western blot. The expressed protein was purified by Ni(2+) affinity chromatography and then renatured by dialysis. The effect of the renatured protein on proliferation of NIH3T3 cells was detected by MTT colorimetry.
Results: Rat betacellulin protein with M(r) being 20 000 was expressed under IPTG induction. The purity of purified protein reached over 96%. After renaturation, the expressed protein could significantly stimulate the proliferation of NIH3T3 cells.
Conclusion: Rat betacellulin gene is successfully cloned into the expression vector pET28a(+) and highly expressed in E.coli. Purified and refolded betacellulin protein can obviously stimulate the proliferation of NIH3T3 cells.