Linked Life Data

7898486

Source:http://linkedlifedata.com/resource/pubmed/id/7898486

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1995-4-27
pubmed:abstractText
We showed previously that the disulfonic stilbene DNDS (4,4'-dinitrostilben-2,2'-disulfonic acid) was a potent blocker of outwardly rectifying chloride channels (ORCC). The studies reported here were designed to quantify the relationship between electron withdrawal by the 4,4'-substituents and blocker potency. Specifically we compared the blocking effects and molecular properties of the symmetrically substituted 4,4'-diaminostilben-2, 2'-disulfonic acid (DADS) and the hemi-substituted 4-amino, 4'-nitrostilben-2,2'-disulfonic acid (ANDS) with those of DNDS. Blockade was studied using outwardly rectifying colonic chloride channels incorporated into planar lipid bilayers. DADS was 430-fold and ANDS 44-fold less potent than DNDS as blockers of ORCC. Amplitude distribution analysis revealed that all three disulfonic stilbenes act as open channel blockers. Furthermore, this kinetic analysis indicated that the lower potency of DADS and ANDS was due to an increase in off rate. These results support the conclusion that the 4,4'-substituents make an important contribution to blockade by stabilizing the channel-blocker complex. Isopotential electron contour maps illustrated the dramatic shift in charge at the 4,4'-poles of the disulfonic stilbene molecule from electronegative in DNDS to electropositive in DADS as well as the bipolar contour of ANDS. Thus, the greater potency of DNDS results from the symmetric electronegative regions at the 4,4'-poles of the molecule. We hypothesize that the channel protein has two corresponding electropositive areas at the blocker binding site.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0300-8177
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
140
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
137-46
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Comparison of -nitro versus -amino 4,4'-substituents of disulfonic stilbenes as chloride channel blockers.
pubmed:affiliation
Department of Physiology and Biophysics, University of Alabama at Birmingham 35294.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't