Linked Life Data

2434028

Source:http://linkedlifedata.com/resource/pubmed/id/2434028

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1987-3-19
pubmed:abstractText
The properties of two monoclonal antibodies which recognize the epsilon subunit of Escherichia coli F1-ATPase were studied in detail. The epsilon subunit is a tightly bound but dissociable inhibitor of the ATPase activity of soluble F1-ATPase. Antibody epsilon-1 binds free epsilon with a dissociation constant of 2.4 nM but cannot bind epsilon when it is associated with F1-ATPase. Likewise epsilon cannot associate with F1-ATPase in the presence of high concentrations of epsilon-1. Thus epsilon-1 activates F1-ATPase which contains the epsilon subunit, and prevents added epsilon from inhibiting the enzyme. Epsilon-1 cannot bind to membrane-bound F1-ATPase. The epsilon-4 antibody binds free epsilon with a dissociation constant of 26 nM. Epsilon-4 can bind to the F1-ATPase complex, but, like epsilon-1, it reverses the inhibition of F1-ATPase by the epsilon subunit. The epsilon subunit remains crosslinkable to both the beta and gamma subunits in the presence of epsilon-4, indicating that it is not grossly displaced from its normal position by the antibody. Presumably the activation arises from more subtle conformational effects. Antibodies epsilon-4 and delta-2, which recognizes the delta subunit, both bind to F1F0 in E. coli membrane vesicles, indicating that these subunits are substantially exposed in the membrane-bound complex. Epsilon-4 inhibits the ATPase activity of the membrane-bound enzyme by about 50%, and Fab prepared from epsilon-4 inhibits by about 40%. This inhibition is not associated with any substantial change in the major apparent Km for ATP. These results suggest that inhibition of membrane-bound F1-ATPase arises from steric effects of the antibody.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0003-9861
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
253
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
73-80
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Activation and inhibition of the Escherichia coli F1-ATPase by monoclonal antibodies which recognize the epsilon subunit.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't