A, Lane 1, 15 µg of total extract from bacteria cells containing pET30a empty vector without IPTG induction; Lane 2, 15 µg of total extract from bacterial cells containing pET30a-SBgLR vector without induction; Lane 3, 20 µg of total extract from bacteria cells containing pET30a-SBgLR vector with 50 mM IPTG induction for 4 h; Lane 4, 10 µg purified SBgLR recombinant protein. B, Lane 1, crude extract of porcine tubulin; Lane 2, purified porcine tubulin. The sizes of protein marker were labeled in the ‘kD’ column.