Linked Life Data

7619827

Source:http://linkedlifedata.com/resource/pubmed/id/7619827

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
28
pubmed:dateCreated
1995-8-30
pubmed:abstractText
In the presence of a suitable electron acceptor such as mammalian cytochrome c, hydroxylamine oxidoreductase (HAO) from the chemolithotrophic bacterium Nitrosomonas europaea catalyzes the oxidation of hydroxylamine or hydrazine to nitrite or dinitrogen, respectively. Each subunit of HAO contains 7 c-hemes and a chromophore of the active site called heme P460, a c-heme bridged from a methylene carbon to a ring carbon of a tyrosine of the peptide chain. Reaction with either substrate results in reduction of several c-hemes of HAO. The reaction of organohydrazines with HAO was investigated in this work. HAO was inactivated by (phenyl-, (methyl-, or (hydroxyethyl)hydrazine. The process followed first order kinetics and was inhibited by the substrates, hydroxylamine or hydrazine. Complete loss of enzyme activity and absorbancy characteristic of native heme P460 of HAO occurred at a 1:1 ratio of phenylhydrazine and HAO. HAO was covalently derivatized by two molecules of [14C]-phenylhydrazine per subunit. Heme P460 was derivatized with high affinity, and an amino acid residue was derivatized with lower affinity. c-Hemes were not derivatized except for the partial reaction of (hydroxyethyl)hydrazine with one heme. As with hydroxylamine and hydrazine, incubation with organohydrazines resulted in reduction of c-heme of HAO. Derivatized minus native optical difference spectra of ferric or ferrous HAO revealed changes in the optical properties of heme P460 which were generally similar to shifts seen in the reaction of the heme of other hemoproteins with organohydrazines.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
18
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9257-64
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Suicide inactivation of hydroxylamine oxidoreductase of Nitrosomonas europaea by organohydrazines.
pubmed:affiliation
Department of Genetics and Cell Biology, University of Minnesota, St. Paul 55108, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.