Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1987-6-25
pubmed:abstractText
A novel approach has been elaborated to identify the mechanism of intermediate transfer in interacting enzyme systems. The aldolase/glycerol-3-phosphate-dehydrogenase enzyme system was investigated since complex formation between these two enzymes had been demonstrated. The kinetics of dihydroxyacetone phosphate conversion catalyzed by the dehydrogenase in the absence and presence of aldolase was analyzed. It was found that the second-order rate constant (kcat/Km) of the enzymatic reaction decreases due to the formation of a heterologous complex. The decrease could be attributed to an increase of the Km value since kcat did not change in the presence of aldolase. In contrast, an apparent increase in the second-order rate constant of dihydroxyacetone phosphate conversion by the dehydrogenase was observed if the triose phosphate was produced by aldolase from fructose 1,6-bisphosphate (consecutive reaction). Moreover, no effect of dihydroxyacetone phosphate on the dissociation constant of the heterologous enzyme complex could be detected by physico-chemical methods. The results suggest that the endogenous dihydroxyacetone phosphate produced by aldolase complexed with dehydrogenase is more accessible for the dehydrogenase than the exogenous one, the binding of which is impeded due to steric hindrance by bound aldolase.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0014-2956
pubmed:author
pubmed:issnType
Print
pubmed:day
4
pubmed:volume
164
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
655-9
pubmed:dateRevised
2007-7-23
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
A simple approach to detect active-site-directed enzyme-enzyme interactions. The aldolase/glycerol-phosphate-dehydrogenase enzyme system.
pubmed:publicationType
Journal Article