FIG. 5.
IEF. (A) IEF and staining with Coomassie blue. Lanes: M, pI marker; GES-3, purified GES-3 enzyme. (B) IEF and staining with nitrocefin. Lanes: 1, GES-3-producing E. coli transformant that harbors pKGB525 carrying blaGES-3; 2, K. pneumoniae KG914; 3, K. pneumoniae KG1116; 4, K. pneumoniae KG525; 5, K. pneumoniae KG545; 6, K. pneumoniae KG502; 7, K. pneumoniae KG827. The bands of pI 7.63 (pI 7.6 in the text) are the chromosomally encoded LEN-1 or SHV-1 β-lactamase of K. pneumoniae, and the bands at pI 6.98 (pI 7.0 in the text) are GES-3. Several β-lactamases with activities at pIs lower than 7.0 were speculated to be partially unfolded GES-3 β-lactamase, because these bands were also found in the IEF gels of an E. coli clone harboring only the blaGES-3 gene (data not shown).