FIGURE 9.

Protein-disulfide reductase activity of recombinant PSA2. The reduction of disulfide bonds in insulin was monitored by an increase in absorbance at 650 nm, which results from insulin precipitation. The reaction was initiated by the addition of dithiothreitol to a final concentration of 100 μm. The ribosome-binding protein RBF1 served as a negative control. All reactions contained BSA. Values represent the mean of three independent assays, each with three replicates. Error bars indicate one S.D.