The Human Recombinant PSP and Its Biological Activity

The objective is to get human recombinant persephin(PSP)and its biological activity.The cDNA encoding the mature human PSP was isolated using RT PCR with total RNA extracted from fetal human brain.The expression plasmid pET PSP was constructed by inserting PSP cDNA into plasmid pET 28a(+)containing T7 promoter and transformed into E.coli BL21(DE3).An expression strain BLPSP was selected.SDS PAGE analysis revealed that the human PSP protein was highly expressed and accumulated up to above 20% of the total bacterial proteins in the form of inclusion body after the induction.By Ni 2+ chelation affinity chromatography,up to 85% PSP protein was purified by one step.Purified and refolded PSP protein could significantly promote the survival of spinal cord neurons.