Figure 4.

The effect of coexpression of vtPA and oxidoreductases in the cytoplasm of strain FA113 (trxB gor supp) quantified by an indirect assay for plasminogen activation using a chromogenic plasmin substrate (see text). Activity has been normalized to the value obtained from vtPA expressed alone in FA113 (column 1). Cell lysates used for columns 2–8 were from strains cotransformed with plasmids pFA2-pFA8, respectively. Plasmids pFA3–8 overexpress active site mutants of TrxA. The amino acid sequence of the active site is listed, along with the known oxidoreductase that contains that native active site.