The whole purification was targeted at EiP fusion protein without considering the in vivo cleaved PAL. (A) Analysis of total protein by SDS-PAGE and by immunoblot using anti-ELP antibody, anti-ELP. Equal amount of total protein was loaded in all lanes. To, extracted by total protein extraction buffer; Bt, extracted by Bt buffer. (B) Relative purification efficiency of EiP from transgenic rice seeds. Samples EX, EXF, DS, DSC, 1CS, 2CS, 3CS, FP and FS, as denoted in the Purification Scheme and Materials and Methods. Recovery percentage of EiP was counted relative to EiP extracted by total protein extraction buffer, and error bar was obtained from three independent experiments. (C–D) Purification of PAL from rice seeds by the ELP-intein system: (C) SDS-PAGE analysis; (D) immunoblot reacted with anti-ELP antibody, anti-ELP and anti-PAL antibody, anti-PAL. Lanes EX, EXF, DS, DSC, 1CS, 2CS, 3CS, FP and FS, as denoted in the Purification Scheme and Materials and Methods; and M, Precision Plus protein Standards (Bio-Rad). Arrows indicated ELP-intein-PAL fusion protein (EiP), cleaved ELP-intein tag (Ei), and purified PAL and N-glycosylated PAL (gPAL).