Linked Life Data

2171927

Source:http://linkedlifedata.com/resource/pubmed/id/2171927

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1990-12-14
pubmed:abstractText
The redox state of cobalt in p-cresolyl cobamide and one of its axial ligands were determined by EPR spectroscopy of Sporomusa ovata as harvested. The analyses revealed that less than 2% (less than 30 nmol/g dry cells) of the total corrinoids (greater than 2400 nmol/g dry cells) were in a low-spin Co(II) complex. The amount increased to about 15% (190-450 nmol/g dry cells) upon partial oxidation by air, indicating that the original valence state of cobalt was a Co(I) prior to this treatment. The cob(I)amide was quantified as Co(III)-CH3 after methylation by iodomethane. More than 45% (1100 nmol/g dry cells) of the extractable corrinoids were in the methylated form, whereas non-treated cells revealed less than 1% (less than 15 nmol g dry cells) of light-sensitive corrinoids. EPR spectra of the Co(II) complex exhibited a threefold N-hyperfine splitting in the gz region, which was similar to vitamin B12. Cells grown with [1.3-15N2]histidine showed a twofold N-hyperfine splitting, demonstrating that the axial N ligand of the corrinoid was derived from the imidazole group of histidine. It is concluded that the super-nucleophilic p-cresolyl cob(I)amide is the major corrinoid complex in vivo and that it is stabilized by its protein(s). The Co(II) ion of the prosthetic group was coordinated by one histidine residue of the apoprotein(s).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
193
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
105-9
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Evidence for a super-reduced cobamide as the major corrinoid fraction in vivo and a histidine residue as a cobalt ligand of the p-cresolyl cobamide in the acetogenic bacterium Sporomusa ovata.
pubmed:affiliation
Abteilung Angewandte Mikrobiologie, Universität Ulm, Federal Republic of Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't