3.5 Periplasmic secretion of FPOX by signal PelB
FPOX successfully expressed in E. coli by connecting PelB
sequence peptide in the protein upstream. PelB signal peptide acts as a
targeting and recognition signal that mediated the transfer of
recombinant FPOX across the inner membrane to periplasm space. Within
the periplasm, the PelB signal peptide was cut by specific signal
peptidase and the recombinant protein has about 2.3 KDa lower weight
after cutting signal peptide. The recombinant FPOX was secreted in the
periplasmic space, however, the main part of FPOX remained in the
inclusion bodies. As showed in Fig.5, the amount of periplasmic protein
in shuffle was higher than of that in BL21. The most level of protein in
the periplasmic space was observed in sample treated with lysozyme in
shuffle that contributes to break the cell wall.