Overexpression and purification of the 45-kDa recombinant GDH protein. The protein was overexpressed and purified as described in Materials and Methods. An SDS-10% polyacrylamide gel stained with Coomassie brilliant blue R-250 is shown. Lanes: M, rainbow molecular size marker in kilodaltons; 1, whole-cell lysate of pOT411 transformant of E. coli TOP10 uninduced; 2, whole-cell lysate of E. coli transformed with pOT411 and induced with arabinose; 3 and 4, different amounts of the recombinant protein purified from pOT411 transformant of E. coli TOP10.