Linked Life Data

6327697

Source:http://linkedlifedata.com/resource/pubmed/id/6327697

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
11
pubmed:dateCreated
1984-7-16
pubmed:abstractText
Hydroxylamine oxidoreductase from Nitrosomonas europeae catalyzes the oxidative conversion of NH2OH to NO-2. The enzyme, Mr = 220,000, has an (alpha beta)3 subunit structure with each alpha beta subunit containing 7-8 c-type hemes and one unusual prosthetic group, termed P-460. The P-460 is also found in a Mr approximately equal to 17,000 protein (P-460 fragment). Mössbauer spectra of the reduced P-460 groups, in hydroxylamine oxidoreductase and the fragment, exhibit nearly identical quadrupole doublets with an unusually large splitting, delta EQ = 4.21 mm/s (no ferrous heme protein is known with delta EQ greater than 2.75 mm/s). The observed isomer shift, delta = 0.96 mm/s at 4.2 K, shows that the P-460 iron is high spin ferrous. Treatment of oxidized hydroxylamine oxidoreductase with H2O2 followed by reduction or exposure of the native sample to CO led to the disappearance of both the characteristic 460 nm absorption band (epsilon = 89 mM-1 cm-1) and the delta EQ = 4.21 mm/s doublet. The iron of the oxidized P-460 fragment is high spin ferric, with Mössbauer and EPR parameters very similar to those of metmyoglobin. Optical spectra of the reduced P-460 fragment show long wavelength bands at 650 and 688 nm which are sensitive to treatment of the fragment with reagents which react with P-460. These bands were, however, not detected in hydroxylamine oxidoreductase. The spectroscopic and chemical evidence obtained to date suggests strongly that the P-460 iron resides in a heme-like macrocycle although the presumed porphyrin must have some unusual features.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
259
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6833-40
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1984
pubmed:articleTitle
Mössbauer, EPR, and optical studies of the P-460 center of hydroxylamine oxidoreductase from Nitrosomonas. A ferrous heme with an unusually large quadrupole splitting.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.