[The high expression of human beta-nerve growth factor in E. coli]

The Hu beta-NGF gene encoding the beta subunit of mature human nerve growth factor was cloned into the pET11c vector under the control of T7 bacteriophage promoter. The SDS-PAGE electrophoresis results of nonreduced recombinant products showed a clear band corresponding to homodimeric (27 kD) form of the molecule. But the SDS-PAGE results of reduced expression protein showed a single band corresponding to monomeric form of Hu beta-NGF (13.5 kD). It represented approximately 14.5% of the total cellular protein. Both of them were immunopositive on Western-Blots with rabbit anti-m beta-NGF polyclonic antibodies. And the recombinant product was biologically active on cultured chicken dorsal root ganglion neurons. So it demonstrated the feasibility of synthesizing the biologically active forms of Hu beta-NGF in E. coli.