[Characterization of membrane-bound Fe(III)-EDTA reductase activities of the thermophilic gram-positive dissimilatory iron-reducing bacterium Thermoterrabacterium ferrireducens].
Whole-cell suspensions of T. ferrireducens reduced Fe(III) citrate, Fe(III)-EDTA, and ferrihydrite with glycerol as an electron donor. After cell disruption, the highest activity was registered with Fe(III)-EDTA as the electron acceptor and NADH or NAD(P)H as electron donors. About 80% of the NAD(P)H-dependent Fe(III)-EDTA reductase activities were associated with the membrane fraction of the cells. Treatment of the membranes with lauryl maltoside led to complete solubilization of the NADH-dependent and 70% solubilization of the NADPH-dependent Fe(III)-EDTA reductase activities. After purification by ion-exchange chromatography, the NADH-dependent activity was concentrated 8-fold, and the NADPH-dependent activity was concentrated 11-fold, with a yield of about 10% for both activities. The Fe(III)-EDTA-reducing enzyme complex included c-type cytochromes and a protein with a molecular mass of ca. 115 k Da, consisting of two polypeptides. This is the first description of membrane-bound Fe(III)-reducing oxidoreductase activities from a gram-positive dissimilatory Fe(III)-reducing bacterium.
Gavrilov
S N
SN
Slobodkin
A I
AI
Robb
F T
FT
de Vries
S
S
D001426:Bacterial Proteins / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D002462:Cell Membrane / Q000187:drug effects / Q000201:enzymology; D002852:Chromatography, Ion Exchange; D002951:Citrates / Q000378:metabolism; D045304:Cytochromes c / Q000378:metabolism; D003902:Detergents / Q000494:pharmacology; D004492:Edetic Acid / Q000378:metabolism; D005290:Ferric Compounds / Q000378:metabolism*; D005960:Glucosides / Q000494:pharmacology; D005990:Glycerol / Q000378:metabolism; D006094:Gram-Positive Bacteria / Q000187:drug effects / Q000201:enzymology*; D007501:Iron; D008970:Molecular Weight; D010084:Oxidation-Reduction; D010088:Oxidoreductases / Q000737:chemistry / Q000302:isolation & purification / Q000378:metabolism*; D012995:Solubility
D001426:Bacterial Proteins; D002951:Citrates; D003902:Detergents; D005290:Ferric Compounds; D005960:Glucosides; C040358:dodecyl maltoside; D045304:Cytochromes c; D004492:Edetic Acid; D007501:Iron; D010088:Oxidoreductases; D005990:Glycerol