Linked Life Data

3015617

Source:http://linkedlifedata.com/resource/pubmed/id/3015617

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1986-9-25
pubmed:abstractText
In the presence of iodide (I-, 10 mM) and hydrogen peroxide in a large excess (H2O2, 0.1-10 mM) catalytic amounts of lactoperoxidase (2 nM) are very rapidly irreversibly inactivated without forming compound III (cpd III). In contrast, in the absence of I- cpd III is formed and inactivation proceeds very slowly. Increasing the enzyme concentration up to the micromolar range significantly accelerates the rate of inactivation. The present data reveal that irreversible inactivation of the enzyme involves cleavage of the prosthetic group and liberation of heme iron. The rate of enzyme destruction is well correlated with the production of molecular oxygen (O2), which originates from the oxidation of excess H2O2. Since H2O2 and O2 per se do not affect the heme moiety of the peroxidase, we suggest that the damaging species may be a primary intermediate of the H2O2 oxidation, such as oxygen in its excited singlet state (1 delta gO2), superoxide radicals (O-.2), or consequently formed hydroxyl radicals (OH.).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
158
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
609-14
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
The role of compound III in reversible and irreversible inactivation of lactoperoxidase.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't