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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1998-6-18
pubmed:abstractText
Phosphofructokinase-1 from Saccharomyces cerevisiae is an octameric enzyme comprising two non-identical subunits, alpha and beta, which are encoded by the unlinked genes PFK1 and PFK2. In this paper, assembly and reactivation of the enzyme have been studied in cell-free extracts of single-deletion mutants. In contrast to the previously described lack of phosphofructokinase-1 activity in cell-free extracts of these mutants, we could measure a temporary enzyme activity immediately after lysis of protoplasts. This result supports the assumption that each of the subunits forms an enzyme structure which is active in vivo but not stable after cell disruption. Upon mixing of separately prepared cell-free extracts of both deletion mutants very low activity could be measured. About 40% of the wild-type activity was regained when both mutants were mixed prior to disruption. The reactivation rate could be slightly increased by addition of ATP and fructose 6-phosphate and was found to be a function of the growth state, particularly of the beta-subunit-carrying cells. The individual subunits did not interact with Cibacron Blue F3G-A, a biomimetic ligand of phosphofructokinase-1. After reassembly of both subunits in vitro a strong affinity of the reconstituted phosphofructokinase-1 to the dye-ligand was observed. The inability of the subunits to reconstitute under certain conditions seems to result from alterations of the intracellular environment following disruption. These changes give rise to induce an unproductive side reaction like self-aggregation of the subunits. Because reconstitution of phosphofructokinase-1 from S. cerevisiae behaves in a similar way to that of hemoglobin and luciferase, we would speculate a general mechanism for assembly of oligomeric proteins in vivo.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0749-503X
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
14
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
323-34
pubmed:dateRevised
2001-11-2
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Assembly of phosphofructokinase-1 from Saccharomyces cerevisiae in extracts of single-deletion mutants.
pubmed:affiliation
Institut für Biochemie, Universitätsklinikum, Universität Leipzig, Germany.
pubmed:publicationType
Journal Article