Comparison of the Effects Induced by Plasma Generated Reactive Species and H2O2 on Lactate Dehydrogenase (LDH) Enzyme

The influence of reactive species (RS) produced by atmospheric-pressure plasma on lactate dehydrogenase (LDH) enzyme in an aqueous solution is examined, and the long-lived RS in the plasma-treated liquid are probed spectrophotometrically. The concentration of RS increases with treatment time and decreases with storage time. The plasma treatment results in the significant change in viability of LDH. Circular dichroism and dynamic light scattering indicate that the change in the activity systems from plasma-induced modification of the secondary molecular structure as well as polymerization of the peptide chains by the RS produced by the plasma. By comparing the plasma treatment of LDH with the H2O2 treatment, the plasma effects are not mediated purely by H2O2 and there are instead synergistic effects in the interactions between the plasma and LDH.