Fig. 5: Characterization of the SOD activity of CuZnHis assemblies.

a The specific activity graph of CuZnHis(L) and CuZnHis(D) according to the scavenging of O2·−. b EPR spectra for the evaluation of O2·− scavenging ability of CuZnHis(L) and CuZnHis(D). c Time-dependent absorbance changes with different concentrations of CuZnHis(L). Smaller difference means stronger O2·− scavenging ability. d EPR spectra for the evaluation of O2·− scavenging ability of CuZnHis(L) in different solvents. e Comparison of SOD activity between CuZnHis(L) and natural SOD at different temperatures. f Comparison of SOD activity between CuZnHis(L) and natural SOD at different pH. In Fig. 5a–f, data are presented as mean ± SD (n = 3).