Plasma
exposure was performed as described for HRP. Enzyme solution was then diluted 1:10 in 100
mM sodium acetate buffer containing 2.5 mM ABTS as substrate. Absorption was followed at
405 nm immediately after adding H2O2 at a final concentration of 1 mM. Background activity
was determined by adding deionized water instead of H2O2. Background activity was
subtracted in all measurements. Data for HRP is taken from Fig 3. 100% represents activity of
untreated samples. Three independent replicates were performed.