Linked Life Data

2334435

Source:http://linkedlifedata.com/resource/pubmed/id/2334435

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1990-6-4
pubmed:abstractText
A purification procedure which yields a near homogenous preparation of phosphoenolpyruvate (PEP) carboxylase from the leaves of Zea mays is reported. The enzyme had a final specific activity of 33.3 micromoles per minute per milligram protein. Size exclusion high performance liquid chromatography and dynamic laser-light scattering spectroscopy showed that PEP carboxylase exists in an equilibrium of aggregates. Enzyme predominantly in the dimeric configuration is less active (when assayed at sub-optimal Mg-PEP concentrations, less than 0.4 millimolar) than when in its tetrameric arrangement. The difference in activity diminishes and disappears as the concentration of the substrate Mg-PEP increases. The substrate drives the equilibrium toward the tetramer, while malate, an inhibitor of PEP carboxylase, shifts the equilibrium toward the dimer. It thus appears that the quaternary structure (oligomeric state) of maize PEP carboxylase can be regulated by the naturally occurring effector molecules Mg-PEP and malate which in turn can control the enzyme's activity.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-291X
pubmed:author
pubmed:issnType
Print
pubmed:day
30
pubmed:volume
168
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
778-85
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
The role of oligomerization in regulation of maize phosphoenolpyruvate carboxylase activity. Influence of Mg-PEP and malate on the oligomeric equilibrium of PEP carboxylase.
pubmed:affiliation
Department of Biochemistry, University of California, Riverside 92521.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.