Linked Life Data

3021195

Source:http://linkedlifedata.com/resource/pubmed/id/3021195

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
1986-12-5
pubmed:abstractText
We have employed electron-nuclear double resonance (ENDOR) spectroscopy to study the 57Fe hyperfine interactions in the bridged-siroheme [4Fe-4S] cluster that forms the catalytically active center of the two-electron-reduced hemoprotein subunit of Escherichia coli NADPH-sulfite reductase (SiR2-). Previous electron paramagnetic resonance (EPR) and Mössbauer studies have shown that this enzyme oxidation state can exist in three distinct spectroscopic forms: (1) a "g = 2.29" EPR species that predominates in unligated SiR2-, in which the siroheme Fe2+ is believed to be in an S = 1 state; (2) a "g = 4.88" type of EPR species that predominates in SiR2- in the presence of small amounts of guanidinium sulfate, in which the siroheme Fe2+ is in an S = 2 state; and (3) a classical "g = 1.94" type of EPR species that is seen in SiR2- ligated with CO, in which the siroheme Fe2+ is in an S = 0 state. In all three species, the cluster is in the [4Fe-4S]1+ state, and two distinct types of Fe site are seen in Mössbauer spectroscopy. ENDOR studies confirm the Mössbauer assignments for the cluster 57Fe in the g = 1.94 state, with A values of 37, 37, and 32 MHz for site I and ca. 19 MHz for site II. The hyperfine interactions are not too different on the g = 2.29 state, with site I Fe showing more anisotropic A values of 32, 24, and 20 MHz (site II was not detected).(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
25
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4647-54
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
57Fe and 1H electron-nuclear double resonance of three doubly reduced states Escherichia coli sulfite reductase.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.