Linked Life Data

15109256

Source:http://linkedlifedata.com/resource/pubmed/id/15109256

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
17
pubmed:dateCreated
2004-4-27
pubmed:abstractText
The hydrophobic cell membrane interior presents a large energy barrier for ions to permeate. Potassium channels reduce this barrier by creating a water-filled cavity at the middle of their ion conduction pore to allow ion hydration and by directing the C-terminal "end charge" of four alpha-helices toward the water-filled cavity. Here we have studied the interaction of monovalent cations with the cavity of the KcsA K(+) channel using X-ray crystallography. In these studies, Tl(+) was used as an analogue for K(+) and the total ion-stabilization energy for Tl(+) in the cavity was estimated by measuring its binding affinity. Binding affinity for the Na(+) ion was also measured, revealing a weak selectivity ( approximately 7-fold) favoring Tl(+) over Na(+). The structures of the cavity containing Na(+), K(+), Tl(+), Rb(+), and Cs(+) are compared. These results are consistent with a fairly large (more negative than -100 mV) electrostatic potential inside the cavity, and they also imply the presence of a weak nonelectrostatic component to a cation's interaction with the cavity.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
4
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
4978-82
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Ion binding affinity in the cavity of the KcsA potassium channel.
pubmed:affiliation
Howard Hughes Medical Institute and Laboratory of Molecular Neurobiology and Biophysics, Rockefeller University, 1230 York Avenue, New York, New York 10021, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S.