Linked Life Data

6350607

Source:http://linkedlifedata.com/resource/pubmed/id/6350607

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1983-10-21
pubmed:abstractText
Two mutant versions of Escherichia coli aspartate transcarbamylase have been purified and analyzed kinetically. Each of these mutant enzymes contains a single amino acid different from the wild-type enzyme, which was introduced by suppression of a nonsense codon within the E. coli pyrB gene. These enzymes exhibited alterations in both homotropic and heterotropic interactions with little change in specific activity. Depending upon the site of the substitution, the allosteric interactions have been either enhanced or diminished over the wild-type enzyme. Carbamyl phosphate saturation curves indicate that aspartate and carbamyl phosphate homotropic co-operativity are separable. Experiments employing the allosteric effectors indicate that the transmission of the regulatory effect is dependent upon the structure of the catalytic subunit, and that CTP inhibition can be partially decoupled from ATP activation. The kinetics of one of the mutants is unusually sensitive to dissociation at elevated temperatures. This sensitivity may be due to weakened interactions between the subunits of the enzyme.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0022-2836
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
168
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
729-45
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1983
pubmed:articleTitle
Analysis of two purified mutants of Escherichia coli aspartate transcarbamylase with single amino acid substitutions.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't