Linked Life Data

216690

Source:http://linkedlifedata.com/resource/pubmed/id/216690

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1979-4-26
pubmed:abstractText
EPR spectroscopic and chemical analyses of spinach nitrite reductase show that the enzyme contains one reducible iron-sulfur center, and one site for binding either cyanide or nitrite, per siroheme. The heme is nearly all in the high spin ferric state in the enzyme as isolated. The extinction coefficient of the enzyme has been revised to E386 = 7.6 X 10(4) cm-1 (M heme)-1. The iron-sulfur center is reduced with difficulty by agents such as reduced methyl viologen (equilibrated with 1 atm of H2 at pH 7.7 in the presence of hydrogenase) or dithionite. Complexation of the enzyme with CO (a known ligand for nitrite reductase heme) markedly increases the reducibility of the iron-sulfur center. New chemical analyses and reinterpretation of previous data show that the enzyme contains 6 mol of iron and 4 mol of acid-labile S2-/mol of siroheme. The EPR spectrum of reduced nitrite reductase in 80% dimethyl sulfoxide establishes clearly that the enzyme contains a tetranuclear iron-sulfur (Fe4S4) center. The ferriheme and Fe4S4 centers are reduced at similar rates (k = 3 to 4 s-1) by dithionite. The dithionite-reduced Fe4S4 center is rapidly (k = 100 s-1) reoxidized by nitrite. These results indicate a role for the Fe4S4 center in catalysis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
254
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1268-72
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1979
pubmed:articleTitle
Identification of the iron-sulfur center of spinach ferredoxin-nitrite reductase as a tetranuclear center, and preliminary EPR studies of mechanism.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.