Linked Life Data

7462245

Source:http://linkedlifedata.com/resource/pubmed/id/7462245

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1981-4-24
pubmed:abstractText
Porcine heart mitochondrial malate dehydrogenase (L-malate:NAD+ oxidoreductase, EC 1.1.1.37) has been immobilized by covalent attachment to CNBr-activated Sepharose 4B-Cl gel. The gel was activated with low levels of CNBr to produce a low density of linkage sites and, hence, to facilitate linkage of the enzyme through a single subunit. Matrix-bound mitochondrial malate dehydrogenase was found to possess 50-65% of the native mitochondrial malate dehydrogenase specific activity when assayed in the NAD+ leads to NADH direction but only 5-15% of the native enzyme specific activity when assayed in the NADH leads to NAD+ direction. MB-dimeric mitochondrial malate dehydrogenase was dissociated to MB-monomer by exposure to pH 5.0 buffer. The MB-monomer was found to be catalytically active, possessing only a slightly decreased specific activity when compared to MB-dimer. The reconstitution of Mb-monomer to MB-dimer was accomplished by adding dissociated mitochondrial malate dehydrogenase, which exists at pH 5.0, to MB-monomer and adjusting to pH 7.5. The kinetic parameters, pH activity profile, and stability toward heat denaturation for MB-mitochondrial malate dehydrogenase (monomer and dimer) were determined and compared to native mitochondrial malate dehydrogenase. MB-mitochondrial malate dehydrogenase exhibited enhanced stability and similar pH activity profiles when compared to native mitochondrial malate dehydrogenase. Immobilization of mitochondrial malate dehydrogenase altered the enzyme's kinetic parameters in such a manner as to increase the values of Km for the substrates and decrease the values of Vmax.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
256
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2383-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1981
pubmed:articleTitle
The immobilization of mitochondrial malate dehydrogenase on Sepharose beads and the demonstration of catalytically active subunits.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.