Linked Life Data

17219451

Source:http://linkedlifedata.com/resource/pubmed/id/17219451

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2007-12-11
pubmed:abstractText
Chelatable cellular iron, and chelatable mitochondrial iron in particular, has yet to be well characterized, so the overall strength with which these "loosely bound" iron ions (presumably mainly Fe(II)) are intracellularly/intramitochondrially bound is unclear. We have previously reported the first selective mitochondrial iron indicator: rhodamine B 4-[(1,10-phenanthrolin-5-yl)aminocarbonyl]benzyl ester (RPA). With this compound as a model, we have now developed two additional mitochondrial iron indicators with very different iron-binding affinities and have applied these to the study of the chelatable iron pool in the mitochondria of isolated rat liver cells. With the new indicator rhodamine B 4-[(2,2'-bipyridin-4-yl)aminocarbonyl]benzyl ester (RDA), with 2,2'-bipyridine as chelating unit (log beta(3)=17.5), essentially the same iron concentration (16.0+/-1.9 microM) was determined as with RPA (log beta(3)=21.1), despite the four orders of magnitude difference in Fe(II)-binding affinity. This not only demonstrates the reliability of the procedure, but also confirms that iron complexation by these indicators does not induce any significant release of iron from the iron-storage proteins on the timescale of the experiment. In contrast, the indicator rhodamine B 4-[bis(pyridin-2-ylmethyl)aminomethyl]benzyl ester (PIRO), with an N,N-bis(pyridin-2-ylmethyl)amine group as chelating component (log beta(2)=12.2), could not compete against the array of endogenous ligands. The intramitochondrial concentrations of the three indicators were determined to be in the range of 100 microM: that is, about three orders of magnitude lower than the total concentration of endogenous compounds that might chelate iron ions. It is therefore estimated that chelatable mitochondrial iron ions are bound by endogenous ligands with apparent stability constants (log K(app)) of between 9 and 14.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1439-4227
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
8
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
341-52
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Assessment of chelatable mitochondrial iron by using mitochondrion-selective fluorescent iron indicators with different iron-binding affinities.
pubmed:affiliation
Institut für Physiologische Chemie, Universitätsklinikum, Hufelandstrasse 55, 45122 Essen, Germany. ursula.rauen@uni-duisburg-essen.de
pubmed:publicationType
Journal Article