Linked Life Data

8804612

Source:http://linkedlifedata.com/resource/pubmed/id/8804612

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1996-12-18
pubmed:abstractText
The conductivity across a lipid bilayer by tetraphenylborate anion is increased 10-fold on the photoformation of lipophilic porphyrin cations. The cations alone have negligible conductivity. This nonlinear photogenerated increase of ion conductivity is termed the photogating effect. Substitution of H by Cl in the para position of tetraphenylborate leads to a 100-fold enhancement of conductivity, whereas the dark conductivities for this and other substituted borates are the same. Moreover, the halo-substituted borates show a large enhancement of conductivity in the low concentration range (10(-8) M), whereas that of tetraphenylborate is small and space charge is negligible. The enhanced ion conductivity has great structural sensitivity to the structure of the anion, the cation, and the lipid, whereas the partition coefficient of all the borates and the concentration of photoformed cations are only slightly affected. The photogated ion transport has a twofold larger activation energy than transport in the dark. Time-resolved photocurrents and voltages demonstrate that the translocation rate of the porphyrin cation is also enhanced 100-fold by the Cl-borate anion but only 10-fold by the H-borate anion. For these reasons the nonlinear gating effect cannot be explained by electrostatics alone, but requires an ion chain or ion aggregate mechanism. Kinetic modeling of the photoinduced current with a mixed cation-anion ion chain can fit the data well. The photogating effect allows the direct study of ion interactions within the bilayer.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/8804612-1148364, http://linkedlifedata.com/resource/pubmed/commentcorrection/8804612-1489912, http://linkedlifedata.com/resource/pubmed/commentcorrection/8804612-1489913, http://linkedlifedata.com/resource/pubmed/commentcorrection/8804612-2223819, http://linkedlifedata.com/resource/pubmed/commentcorrection/8804612-2424473, http://linkedlifedata.com/resource/pubmed/commentcorrection/8804612-2476808, http://linkedlifedata.com/resource/pubmed/commentcorrection/8804612-2660821, http://linkedlifedata.com/resource/pubmed/commentcorrection/8804612-3416031, http://linkedlifedata.com/resource/pubmed/commentcorrection/8804612-3756296, http://linkedlifedata.com/resource/pubmed/commentcorrection/8804612-5579131, http://linkedlifedata.com/resource/pubmed/commentcorrection/8804612-620077, http://linkedlifedata.com/resource/pubmed/commentcorrection/8804612-6266334, http://linkedlifedata.com/resource/pubmed/commentcorrection/8804612-6275448, http://linkedlifedata.com/resource/pubmed/commentcorrection/8804612-7260322, http://linkedlifedata.com/resource/pubmed/commentcorrection/8804612-8396456, http://linkedlifedata.com/resource/pubmed/commentcorrection/8804612-946975, http://linkedlifedata.com/resource/pubmed/commentcorrection/8804612-999935
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-3495
pubmed:author
pubmed:issnType
Print
pubmed:volume
71
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
295-308
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1996
pubmed:articleTitle
Evidence for ion chain mechanism of the nonlinear charge transport of hydrophobic ions across lipid bilayers.
pubmed:affiliation
Rockefeller University, New York, New York 10021, USA.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, P.H.S.