A novel iron protein from Desulfovibrio gigas.
The isolation, purification, and partial characterization of a novel iron-containing protein from the sulfate-reducing anaerobic bacterium, Desulfovibrio gigas, is described. The highly insoluble protein was isolated from the cell debris following osmotic shock of the bacteria. The insoluble fraction consistently contained about 90% of the cell-associated iron. Elemental analysis of a crude protein preparation gave 5.3% iron, 2.9% sulfur and 11.9% nitrogen. An independent colorimetric iron analysis showed 6.4% iron. The iron could be dissociated from the protein by treatment with 5% SDS. The iron-free protein was purified by a combination of organic extraction and DEAE-cellulose chromatography. The purified protein showed only one major band, Mr 14000, by SDS-polyacrylamide gel electrophoresis. The protein could be reconstituted upon treatment with an appropriate mixture of FeS and beta-mercaptoethanol. The reconstituted protein had the same physical and chemical properties as the native protein. The amino acid composition was not unusual except for the high isoleucine content.
D000596:Amino Acids / Q000032:analysis; D001426:Bacterial Proteins / Q000302:isolation & purification*; D003901:Desulfovibrio / Q000378:metabolism*; D007501:Iron / Q000378:metabolism; D007506:Iron-Sulfur Proteins / Q000302:isolation & purification*; D008667:Metalloproteins / Q000302:isolation & purification* / Q000378:metabolism; D019159:Nonheme Iron Proteins; D013053:Spectrophotometry
D000596:Amino Acids; D001426:Bacterial Proteins; D007506:Iron-Sulfur Proteins; D008667:Metalloproteins; D019159:Nonheme Iron Proteins; C022220:desulforedoxin; D007501:Iron