Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5 Pt 1
pubmed:dateCreated
1993-6-22
pubmed:abstractText
Eosin-5-maleimide (EM) has been used as a fluorescent probe for the external-facing transport site of the human erythrocyte band 3 protein. Changes in chloride concentration at both sides of the membrane have no significant effect on the inhibitory potency of EM as a reversible inhibitor of Cl- exchange at 0 degrees C, however, demonstrating that it is not a competitive inhibitor. The affinity of EM for the form of band 3 with the transport site facing outward is approximately five times greater than for the form with the transport site facing the cytoplasm; binding of iodide to the external transport site causes no statistically significant decrease in affinity for EM. Eosin, without the maleimide moiety, is a slightly more potent inhibitor than is EM. Erythrosin, an analogue with four iodide atoms replacing the four bromide atoms in eosin, is a much more potent inhibitor, with a half-inhibitory concentration of only 3.1 microM, > 30 times lower than that of EM. Neither eosin nor erythrosin inhibition is affected by changes in chloride concentration as would be expected for a competitive inhibitor. Thus EM and the other eosin derivatives bind to a site separate from the external transport site, but one that is affected by the changes of transport site conformation from the inward-facing to the outward-facing state.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
264
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C1144-54
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Eosin-5-maleimide inhibits red cell Cl- exchange at a noncompetitive site that senses band 3 conformation.
pubmed:affiliation
Department of Biophysics, University of Rochester Medical Center, New York 14642.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.