Preparation and characterization of the hydrophilic CuA-cytochrome c domain of subunit II of cytochrome c oxidase from thermophilic bacillus PS3.
Cytochrome c oxidase of the thermophilic bacterium, PS3, was treated with trypsin. The hydrophilic domain of 26 kDa can be easily cleaved off from the hydrophobic anchor domain at the N-terminal region of subunit II, but remains attached to the rest of the enzyme upon gel-filtration in the presence of 0.2% lauroyl sarcosinate. The separation occurred in the presence of 5 M urea in addition to 0.2% lauroyl sarcosinate. After relatively prolonged proteolysis, that induced severe activity decay, and subunit I fragmentation, the 26 kDa fragment of subunit II can be easily isolated from the rest, suggesting that this fragment with cytochrome c and CuA interacts with subunit I. The separated fragment showed absorption spectra due to CuA and cytochrome c. Reconstitution of the cytochrome oxidase activity occurred on addition of the 26 kDa fragment to the proper gel-filtration chromatographic fraction.
Tashiro
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H
Department of Biochemical Engineering and Science, Kyushu Institute of Technology, Fukuoka.
Sone
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D000595:Amino Acid Sequence; D001407:Bacillus / Q000145:classification / Q000201:enzymology*; D003574:Cytochrome c Group / Q000737:chemistry*; D045304:Cytochromes c; D003576:Electron Transport Complex IV / Q000737:chemistry*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010446:Peptide Fragments / Q000737:chemistry*; D017434:Protein Structure, Tertiary; D012995:Solubility; D014357:Trypsin; D014867:Water / Q000737:chemistry
D003574:Cytochrome c Group; D010446:Peptide Fragments; C036304:copper cytochrome c; D014867:Water; D045304:Cytochromes c; D003576:Electron Transport Complex IV; D014357:Trypsin