title: Potentiometric titration of the high- and low-potential 4Fe-4S* centers of Azotobacter vinelandii ferredoxin I.
abstract: The high-potential 4Fe-4S* center ofAzotobacter vinelandii ferredoxin I has been titrated potentiometrically by a reductive procedure. The absorbance decrease at 510 nm accompanying the reduction of the high-potential center titrated with an Em of 320 mV (n = 1). The low-potential 4Fe-4S* center was titrated by using the absorbance decrease at 410 nm to monitor its reduction. This center exhibited an Em of -424 mV (n = 1).
mesh_terms: D001395:Azotobacter / Q000032:analysis*; D005288:Ferredoxins / Q000378:metabolism*; D007501:Iron / Q000378:metabolism; D007700:Kinetics; D010084:Oxidation-Reduction; D013440:Sulfides / Q000378:metabolism
chemical_list: D005288:Ferredoxins; D013440:Sulfides; D007501:Iron