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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
18
pubmed:dateCreated
1980-11-24
pubmed:abstractText
The EPR spectra of the NO complexes of frozen solutions of ascorbic acid-reduced cytochrome oxidase (nitrite reductase) purified from Pseudomonas aeruginosa, of its heme d1-depleted form, and of heme d1 in solutions containing various nitrogenous bases are quite similar to each other as well as to several heme (iron protoporphyrin IX)-containing proteins. The NO complexes of heme d1 (an iron-chlorin) in the presence of nitrogenous bases belong to spectral type C according to Kon's classification and, thus, the energy levels of the iron are closely related to thorse of heme complexes recorded under similar conditions. Comparison of these spectra with those of complexes of known structure suggests that both heme c and heme d1 are linked with Pseudomonas cytochrome oxidase by means of a nitrogenous ligand. The EPR spectrum of the NO complex of the native enzyme exhibits a lack of resolution of the high field (gy) resonance which can be characterized in terms of a spectral contribution from both the heme c and heme d1 moieties. The similarity between the EPR spectra of the NO complexes of horse heart cytochrome c and the heme d1-depleted Pseudomonas cytochrome oxidase before and after interaction with urea suggests structural similarities involving the heme irons. The changes caused by urea are likely to be a breaking or distortion of the bond between the iron and the protein-donated nitrogenous ligand and are similar to alterations seen with NO complexes of hemoglobin under a variety of conditions.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
255
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
8437-42
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1980
pubmed:articleTitle
EPR study of heme x NO complexes of ascorbic acid-reduced Pseudomonas cytochrome oxidase and corresponding model complexes.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.