Linked Life Data

7705358

Source:http://linkedlifedata.com/resource/pubmed/id/7705358

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1995-5-9
pubmed:abstractText
1. The murine liver enzyme homogenisate 1,2-dioxygenase (HGO) is purified 330-fold. The molecular mass, as determined by gel filtration, is approximately 149 kDa. SDS/PAGE under strongly reducing conditions reveals a single band at 49 kDa, whose concentration increases during the purification. 2. HGO has a pI = 8. The pH optimum for activity in vitro is 6.1. 3. The Km for its natural substrate HGA is 188 microM, whereas the Kd for the ferrous ion is determined at 19 microM. Fe2+ is an absolutely obligate cofactor and cannot be replaced by other divalent cations. Incubating the enzyme with Fe2+ plus one of other divalent cations Zn2+, Cu2+, Co2+ or Ni2+ in equimolar concentrations inhibits HGO, whereas addition of Ca2+ and Mn2+ has no effect. Ascorbate probably acts as a reducing agent, protecting Fe2+ from spontaneous oxidation or by reversing its oxidation. Ascorbate has a great potential to stabilize the assay system. 4. The activation energy determined by an Arrhenius plot is 24 kJ/mol. 5. HGO consists of a single type of subunit with no intermolecular disulfide bridges and requires Fe2+ as a cofactor. This emphazises that the enzyme is familiar with the class of extradiol dioxygenases.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
228
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
425-30
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Murine liver homogentisate 1,2-dioxygenase. Purification to homogeneity and novel biochemical properties.
pubmed:affiliation
Department of Human Genetics, University of Würzburg, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't