The soluble fraction of recombinant protein from the cell lysate
was purified under native conditions with increased concentration
of imidazole in elution buffer. Under native conditions only 12 mg/
l of protein was purified in case of pET28a(+) vector and large fraction
of protein was present in lysed cell pellet confirming the presence
of expressed protein in inclusion bodies. In case of pQE30UA
vector, 1.2 mg/l was eluted under native conditions and no clear
band of purified protein was observed in gel. In both the vectors,
the protein was observed in the lysed cell pellet and purification
under denaturing conditions was required to get the maximum
yield of purified protein