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rdf:type |
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lifeskim:mentions |
umls-concept:C0010505,
umls-concept:C0010798,
umls-concept:C0014834,
umls-concept:C0030685,
umls-concept:C0205099,
umls-concept:C0391871,
umls-concept:C0392756,
umls-concept:C0439855,
umls-concept:C0680255,
umls-concept:C0968573,
umls-concept:C1167622,
umls-concept:C1283071,
umls-concept:C1442792,
umls-concept:C1963578,
umls-concept:C2603343
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pubmed:issue |
8
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pubmed:dateCreated |
1996-6-21
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pubmed:abstractText |
Cyanide-binding to the heme-copper binuclear center of bo-type ubiquinol oxidase from Escherichia coli was investigated with Fourier transform-infrared and EPR spectroscopies. Upon treatment of the air-oxidized CN-inhibited enzyme with excess sodium dithionite, a 12C-14N stretching vibration at 2146 cm-1 characteristic of the FeO3+ C=N CuB2+ bridging structure was quickly replaced with another stretching mode at 2034.5 cm-1 derived from the FeO2+ C=N moiety. The presence of ubiquinone-8 or ubiquinone-1 caused a gradual autoreduction of the metal center(s) of the air-oxidized CN-inhibited enzyme and a concomitant appearance of a strong cyanide stretching band at 2169 cm-1. This 2169 cm-1 species could not be retained with a membrane filter (molecular weight cutoff = 10,000) and showed unusual cyanide isotope shifts and a D2O shift. These observations together with metal content analyses indicate that the 2169 cm-1 band is due to a CuB.CN complex released from the enzyme. The same species could be produced by anaerobic partial reduction of the CN-inhibited ubiquinol oxidase and, furthermore, of the CN-inhibited cytochrome c oxidase; but not at all from the fully reduced CN-inhibited enzymes. These findings suggest that there is a common intermediate structure at the binuclear center of heme-copper respiratory enzymes in the partially reduced state from which the CuB center can be easily released upon cyanide-binding.
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
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pubmed:status |
MEDLINE
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pubmed:month |
Feb
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pubmed:issn |
0021-9258
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:day |
23
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pubmed:volume |
271
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
4017-22
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:8626734-Anaerobiosis,
pubmed-meshheading:8626734-Animals,
pubmed-meshheading:8626734-Binding Sites,
pubmed-meshheading:8626734-Cattle,
pubmed-meshheading:8626734-Copper,
pubmed-meshheading:8626734-Cyanides,
pubmed-meshheading:8626734-Cytochrome b Group,
pubmed-meshheading:8626734-Cytochromes,
pubmed-meshheading:8626734-Electron Spin Resonance Spectroscopy,
pubmed-meshheading:8626734-Electron Transport Complex IV,
pubmed-meshheading:8626734-Escherichia coli,
pubmed-meshheading:8626734-Escherichia coli Proteins,
pubmed-meshheading:8626734-Heme,
pubmed-meshheading:8626734-Mitochondria, Heart,
pubmed-meshheading:8626734-Mutagenesis, Site-Directed,
pubmed-meshheading:8626734-Oxidation-Reduction,
pubmed-meshheading:8626734-Point Mutation,
pubmed-meshheading:8626734-Protein Binding,
pubmed-meshheading:8626734-Recombinant Proteins,
pubmed-meshheading:8626734-Spectroscopy, Fourier Transform Infrared
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pubmed:year |
1996
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pubmed:articleTitle |
Infrared and EPR studies on cyanide binding to the heme-copper binuclear center of cytochrome bo-type ubiquinol oxidase from Escherichia coli. Release of a CuB-cyano complex in the partially reduced state.
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pubmed:affiliation |
Department of Life Science, Faculty of Science, Himeji Institute of Technology, Kamigoori-cho, Akou-gun, Hyogo 678-12, Japan.
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pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, Non-U.S. Gov't
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