The active center of superoxide dismutase from Propionibacterium shermanii

Manipulating the coordination mumber of the ferric iron within the cambialistic superoxide dismutase of Propionibacterium shermanii by changing the pH‐value

“…Therefore, the reduction of the activity might be due to changes of the electrostatic interaction with the substrate. X‐ray absorption spectroscopy (XAS), Mössbauer and EPR measurements performed on both lpH‐SODs and fpH‐SODs [5–7] give evidence for a change of the central metal’s coordination number from five to six due to an increase in the pH value. This could favor the hypothesis that at high‐pH values, inhibition may occur via a molecule that enhances the coordination number of iron.…”

“…The X‐ray structure of the P. shermanii Fe‐SOD was solved recently [9] at pH 6.1. The iron is in the ferric Fe(III) state within the entire pH range [6] and is pentacoordinated at low‐pH. To show the complete structure of the hexacoordinated state predicted by XAS, the X‐ray structures of the Fe‐SOD of P. shermanii at different pH values and at different temperatures are presented.…”