A. SDS-PAGE analysis of SjOAR expression from E. coli BL21 transformed with the recombinant plasmid SjOAR-pET28a. M, molecular weight marker; lane 1, whole lysate of bacterial without induction; lane 2 and lane 3, whole lysate and supernatant of bacteria induced with 1 mM IPTG at 37°C for 6 h. B. Elution profile of SjOAR on a gel chromatography column. BSA with a molecular weight of 67 KDa (monomer) was used as an internal control. The insert figure shows a single band on an SDS-PAGE gel. C. Identification of rSjOAR by western blotting. M, prestained protein marker; lane 1, the purified His-tag fusion SjOAR protein was probed with rabbit anti-His antibody (1:2,000 diluted in PBST buffer). The secondary antibody was horseradish peroxidase (HRP)-conjugated goat anti-rabbit IgG antibody (1: 8,000 diluted in PBST buffer). Chromogenic detection was performed using 3, 3′-diaminobenzidine (Sigma, USA). The arrow indicates the target band, assumed to be SjOAR protein.