Fig. 4

SDS-PAGE analysis of the expressed proteins of recombinant pET-30a(+)-pcaGH. M, protein marker; 1, The total protein of non-deduced E. coli BL21 (DE3) containing pET-30a(+)-pcaGH; 2: The secretory protein in the medium; 3, The total protein of E. coli BL21 (DE3) containing pET-30a(+)-pcaGH induced with IPTG for 4 h; 4, The precipitate protein obtained by ultrasonication and centrifugation; 5: The supernatant protein obtained by ultrasonication and centrifugation. The arrows indicate the positions of the expressed α and β subunits