Linked Life Data

7929161

Source:http://linkedlifedata.com/resource/pubmed/id/7929161

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
40
pubmed:dateCreated
1994-11-4
pubmed:abstractText
Three double cysteine mutants, each possessing a disulfide bond in its pore-forming domain, were used to study the translocation of colicin A through the Escherichia coli envelope. These mutated colicins were able to exert their in vivo channel activity only after their disulfide bonds had been reduced by dithiothreitol. In solution, the reduction of the disulfide bonds by dithiothreitol was a slow process whose kinetics depended on the position of the disulfide bond (t1/2 varying between 35 and 100 s). This t1/2 was strongly decreased (t1/2 = 8-9 s) upon predenaturation of the mutated colicins with urea. The t1/2 values of reduction of the mutants bound to E. coli-sensitive cells were similar to those of predenatured colicins. This suggested that the interaction of the oxidized double cysteine mutants with the E. coli envelope triggered their unfolding. The disulfide bonds did not prevent but delayed the translocation of the colicins. The amplitude of the delay and the time at which it occurred during translocation depended on the position of the disulfide bond. We could discriminate between the delays accumulated during binding to the receptor and those during the translocation via OmpF and the Tol proteins.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
269
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
24820-5
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Unfolding of colicin A during its translocation through the Escherichia coli envelope as demonstrated by disulfide bond engineering.
pubmed:affiliation
Laboratoire d'Ingénierie et de Dynamique des Systèmes Membranaires, Centre de Biochimie et de Biologie Moleculaire, Marseille.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't