In vivo formation of Cu,Zn superoxide dismutase disulfide bond in Escherichia coli

We have found that the in vivo folding of periplasmic Escherichia coli Cu,Z n superoxide dismutase is assisted by DsbA, which catalyzes the efficient f ormation of its single disulfide bond, whose integrity is essential to ensu re full catalytic activity. to the enzyme, In line with these findings, we also report that the production of recombinant Xenopus laevis Cu,Zn superox ide dismutase is enhanced when the enzyme is exported in the periplasmic sp ace or is expressed in thioredoxin reductase mutant strains. Our data show that inefficient disulfide bond oxidation in the bacterial cytoplasm inhibi ts Cu,Zn superoxide dismutase folding in this cellular compartment, (C) 199 9 Federation of European Biochemical Societies.