Linked Life Data

188480

Source:http://linkedlifedata.com/resource/pubmed/id/188480

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1977-3-31
pubmed:abstractText
1. Diverse classes of compounds such as dicarboxylates, pyrophosphates, quinols and nitrophenols are known to activate mitochondrial succinate dehydrogenase (EC 1.3.99.1). Examples in each class -- malonate, pyrophosphate, ubiquinol and 2,4-dinitrophenol -- are selected for comparative studies on the kinetic constants and structural relationship. 2. The activated forms of the enzyme obtained on preincubating mitochondria with the effectors exhibited Michaelian kinetics and gave double-reciprocal plots which are nearly parallel to that of the basal form. On activation, Km for the substrate also increased along with V. The effectors activated the enzyme at low concentrations and inhibited, in a competitive fashion, at high concentrations. The binding constant for activation was lower than that for inhibition for each effector. 3. These compounds possess ionizable twin oxygens separated by a distance of 5.5 +/- 0.8 A and having fractional charges in the range of -0.26 to -0.74 e. The common twin-oxygen feature of the substrate and the effectors suggested the presence of corresponding counter charges in the binding domain. The competitive nature of effectors with the substrate for inhibition further indicated the close structural resemblance of the activation and catalytic sites.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
11
pubmed:volume
480
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
47-55
pubmed:dateRevised
2000-12-18
pubmed:meshHeading
pubmed:year
1977
pubmed:articleTitle
Structural and kinetic studies on the activators of succinate dehydrogenase.
pubmed:publicationType
Journal Article