Linked Life Data

2831955

Source:http://linkedlifedata.com/resource/pubmed/id/2831955

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1988-4-28
pubmed:abstractText
Cytochrome c oxidase in which the CuA site has been perturbed by extensive modification of the enzyme with the thiol reagent p-(hydroxymercuri)benzoate has been reconstituted into phospholipid vesicles. The reconstituted vesicles lack respiratory control, and the orientation of the enzyme in the vesicles is similar to that of the native cytochrome c oxidase. In the proton translocation assay, the vesicles containing the modified enzyme behave as if they are unusually permeable to protons. When the modified and native proteins were coreconstituted, a substantial portion of the latter became uncoupled as revealed by low respiratory control and low overall proton pumping activity. These results suggest that the modified enzyme catalyzes a passive transport of protons across the membrane. When milder conditions were used for the chemical modification, a majority of the thiols reacted while the CuA site remained largely intact. Reconstitution of such a partially modified cytochrome c oxidase produced vesicles with respiratory control and proton translocating activity close to those of reconstituted native enzyme. It thus appears that the appearance of a proton leak is related to the perturbation of the CuA site. These observations suggest that the structure of CuA may be related to the role of this site in the proton pumping machinery of cytochrome c oxidase.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
12
pubmed:volume
27
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
296-301
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Chemical modification of the CuA site affects the proton pumping activity of cytochrome c oxidase.
pubmed:affiliation
Arthur Amos Noyes Laboratory of Chemical Physics, California Institute of Technology, Pasadena 91125.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't