Linked Life Data

1089657

Source:http://linkedlifedata.com/resource/pubmed/id/1089657

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1975-5-21
pubmed:abstractText
2-Nitro-4-azidophenyl-1-thio-beta-D-galactopyranoside (azidophenylgalactoside) is a competitive inhibitor of lactose transport in membrane vesicles isolated from Escherichia coli ML 308-225, exhibiting an apparent Ki of 75 muM. The initial rate and steady state level of [3H]azidophenylgalactoside accumulation are markedly stimulated by the addition of D-lactate to vesicles containing the lac transport system, and kinetic studies reveal an apparent Km of 75 muM. Membrane vesicles devoid of the lac transport system do not take up significant amounts of azidophenylgalactoside in the presence or absence of D-lactate. When exposed to visible light in the presence of D-lactate, azidophenylgalactoside irreversibly inactivates the lac transport system. Strikingly, photolytic inactivation is not observed in the absence of D-lactate. Kinetic studies of the inactivation process yield a KD of 77 muM. Since lactose protects against inactivation and azidophenylgalactoside does not inactivate amino acid transport, it is apparent that these effects are specific for the lac transport system. The results are consistent with the proposal that the lac carrier protein is inaccessible to substrate in the absence of energy coupling.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
25
pubmed:volume
250
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1371-5
pubmed:dateRevised
2009-10-27
pubmed:meshHeading
pubmed:year
1975
pubmed:articleTitle
Photoinactivation of the beta-galactoside transport system in Escherichia coli membrane vesicles with 2-nitro-4-azidophenyl-1-thio-beta-D-galactopyranoside.
pubmed:publicationType
Journal Article