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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1987-1-22
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pubmed:abstractText |
Passage of F1-ATPase through a centrifuge column [Penefsky, H. S. (1979) Methods Enzymol. 56, 527-530] caused formation of a product with a relative molecular mass of 72,000 as determined by sodium dodecyl sulfate/polyacrylamide gel electrophoresis. The product was identified as cross-linked alpha and delta subunits by using Western blots and subunit-specific monoclonal antibodies. The cross-link was reversed by 50 mM dithiothreitol implying that it was a disulfide bridge. Formation of the cross-link was inhibited by 2 mM EDTA and was stimulated in some buffers by the addition of 10 microM CuCl2. Time course experiments indicated that the majority of the cross-link formed while the enzyme was passing through the column. Thus the cross-link induced by column centrifugation arose from the rapid, heavy-metal-ion-catalysed oxidation of two sulfhydryl groups, one on the alpha subunit and one on the delta subunit, to a disulfide. These results demonstrate that care must be exercised when running proteins through centrifuge columns as potentially deleterious disulfide formation can result. An anti-beta monoclonal antibody was capable of immunoprecipitating the entire enzyme including the cross-linked subunits, implying that the cross-linked alpha and delta subunits were still a part of F1. The formation of the cross-link affected neither the hydrolytic activity of the enzyme nor its susceptibility to inhibition by epsilon subunit. The cross-linked enzyme was unable to bind to F1-depleted membranes in experiments in which soluble F1 and membranes were separated by centrifugation. Column centrifugation did not generate the cross-link on membrane-bound enzyme. These results indicate that the alpha-delta cross-link results in a loss of binding affinity between F1 and F0.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Dec
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pubmed:issn |
0014-2956
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
1
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pubmed:volume |
161
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
513-8
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pubmed:dateRevised |
2007-7-23
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pubmed:meshHeading |
pubmed-meshheading:2877881-Antibodies, Monoclonal,
pubmed-meshheading:2877881-Bridged Compounds,
pubmed-meshheading:2877881-Centrifugation,
pubmed-meshheading:2877881-Disulfides,
pubmed-meshheading:2877881-Electrophoresis, Polyacrylamide Gel,
pubmed-meshheading:2877881-Escherichia coli,
pubmed-meshheading:2877881-Proton-Translocating ATPases
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pubmed:year |
1986
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pubmed:articleTitle |
Column centrifugation generates an intersubunit disulfide bridge in Escherichia coli F1-ATPase.
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pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
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