Isolation and role of nonheme iron protein in Clostridium botulinum.

A type of iron-bound protein was isolated from Clostridium botulinum by a modification of the method used for isolating ferredoxin from C. pasteurianum. This method involved acetone and diethylaminoethyl cellulose treatments followed by ammonium sulfate fractionation. The protein exhibited maximal absorption in the ultraviolet region near 260 mmu. Portions of the isolated iron protein were separated by disc electrophoresis and, following specific iron-bound protein staining, showed a positive reaction in the same position on the gel column as was first demonstrated by use of cell-free extract. Evidence accumulated by use of a cell-free extract of C. botulinum suggests that pyruvate is metabolized through a phosphoroclastic system as demonstrated in other clostridia. It is probable that ferredoxin is an electron mediator between pyruvic oxidase and hydrogenase for hydrogen evolution and acetyl phosphate formation.