Linked Life Data

1314660

Source:http://linkedlifedata.com/resource/pubmed/id/1314660

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
1992-5-28
pubmed:abstractText
The question of the possible identity of catalytic and regulatory proton pathways in the chloroplast FoF1 ATPase has been studied using different energy-transfer inhibitors. Venturicidin, a reversible inhibitor of Fo, affects neither the delta mu H(+)-dependent thiol reduction of the membrane-bound chloroplast ATPase nor its ability to be activated by the proton gradient. It seems therefore to block only the proton flow required by the catalytic function of the enzymes. Venturicidin, however, also slows down the deactivation of the thiol-reduced ATPases during uncoupled ATP hydrolysis, following a delta mu H+ activation, but phloridzin, a reversible F1 inhibitor, has the same effect. Tentoxin, an irreversible F1 inhibitor, decreases the rate of ATP hydrolysis but does not affect the rate of deactivation. These findings suggest that catalytic and regulatory H(+)-binding sites are different. No distinction can be made, if any, between protons involved in unmasking the thiol-sensitive groups of F1 and in activating the enzyme. The effect of venturicidin and phloridzin on the deactivation is consistent with an inhibitory effect of newly formed--by ATP hydrolysis--ADP molecules, which might affect the enzyme without passing through the medium. Phosphate at millimolar concentration has an effect similar to low concentrations of phloridzin and venturicidin, probably by a simple back-reaction effect.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
31
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4239-47
pubmed:dateRevised
2001-11-2
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
An attempt to discriminate catalytic and regulatory proton binding sites in membrane-bound, thiol-reduced chloroplast ATPase.
pubmed:affiliation
Biosystèmes Membranaires, CNRS, Gif-sur-Yvette, France.
pubmed:publicationType
Journal Article