Linked Life Data

7819201

Source:http://linkedlifedata.com/resource/pubmed/id/7819201

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1995-2-16
pubmed:abstractText
FixL is a ferrous heme protein whose kinase activity is inhibited by oxygen. Here we show that met-FixL, which is the ferric unliganded form, has the same activity as deoxy-FixL, the ferrous unliganded form, indicating that activity does not depend on the oxidation state of the heme iron. The ferric derivative fluoro-FixL is fully active, indicating that the presence of a heme ligand is not sufficient to cause kinase inhibition. An inverse relation between the rate of autophosphorylation of ferric FixL and the fractional saturation with cyanide shows that the cyanomet form has zero activity. All our active derivatives were high-spin, while our inactive derivatives were low-spin. In mixtures of high- and low-spin FixL, resulting from partial saturation with low-spin ligands, the activity was that which would be expected for the concentration of the high-spin component alone. Therefore the spin state of the heme iron rather than the oxidation state or presence of ligands must be the factor that controls FixL's kinase activity. On transition from low to high spin, the heme iron moves out of the porphyrin plane by 0.4 A. We propose that, as in hemoglobin, this motion triggers a long-range conformational change which in FixL is responsible for a switch to an active form.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
232-6
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Kinase activity of oxygen sensor FixL depends on the spin state of its heme iron.
pubmed:affiliation
Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't