Reactivation of cPGIs from P. furiosus, A. fulgidus, M. mazei, and S. enterica serovar Typhimurium by metals after EDTA treatment and subsequent H2O dialyses. (A) PfcPGI; (B) AfcPGI; (C) MmcPGI; (D) StcPGI. Reactivation obtained with Fe2+ (▪), Ni2+ (•), Mn2+ (▴), and Zn2+ (▾) is shown. A total of 100% of the specific activity corresponds to 91 U/mg (PfcPGI), 7 U/mg (AfcPGI), 2.3 U/mg (MmcPGI), or 1.2 U/mg (StcPGI).