Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
12
pubmed:dateCreated
1990-6-20
pubmed:abstractText
The effects of nonylphenol and 3,5-dibutyl-4-hydroxytoluene (BHT) on the activity of the (Ca2(+)-Mg2+)-ATPase of skeletal muscle sarcoplasmic reticulum have been studied. At high concentrations, both inhibit the ATPase activity of the ATPase either in native lipid or in bilayers of dioleoylphosphatidylcholine but, at low concentrations, an increase in ATPase activity is observed, particularly for the ATPase reconstituted into dimyristoleoylphosphatidylcholine. Neither nonylphenol nor BHT binds at the lipid-protein interface of the ATPase. Nonylphenol decreases the effective equilibrium constant for phosphorylation of the ATPase by Pi probably through an increase in the effective rate of dephosphorylation of the phosphorylated ATPase. It also decreases the effective rate of the E2-Ca2E1 transition and increases the effective equilibrium constant E2/E1 for the ATPase. Inhibition of ATPase activity follows from the slowing of the E2-E1 transition despite increases in effective rates for dephosphorylation and for the transport step, Ca2E1P-E2P. Since nonylphenol has been shown to affect equilibrium constants for various steps in the reaction pathway of the ATPase, inhibition of activity of the ATPase cannot follow from effects on the fluidity (viscosity) of the membrane, since fluidity alone cannot affect equilibrium properties of the system.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
27
pubmed:volume
29
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3091-101
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Mechanism of inhibition of the (Ca2(+)-Mg2+)-ATPase by nonylphenol.
pubmed:affiliation
Department of Biochemistry, University of Southampton, U.K.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't