Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1996-4-29
pubmed:abstractText
Conductance noise measurement of the open states of alamethicin transmembrane channels reveals excess noise attributable to cooperative low-frequency molecular dynamics that can generate fluctuations approximately 1 A rms in the effective channel pore radius. Single-channel currents through both persistent and nonpersistent channels with multiple conductance states formed by purified polypeptide alamethicin in artificial phospholipid bilayers isolated onto micropipettes with gigaohm seals were recorded using a voltage-clamp technique with low background noise (rms noise < 3 pA up to 20 kHz). Current noise power spectra between 100 Hz and 20 kHz of each open channel state showed little frequency dependence. Noise from undetected conductance state transitions was insignificant. Johnson and shot noises were evaluated. Current noise caused by electrolyte concentration fluctuation via diffusion was isolated by its dependence on buffer concentration. After removing these contributions, significant current noise remains in all persistent channel states and increases in higher conductance states. In nonpersistent channels, remaining noise occurs primarily in the lowest two states. These fluctuations of channel conductance are attributed to thermal oscillations of the channel molecular conformation and are modeled as a Langevin translational oscillation of alamethicin molecules moving radially from the channel pore, damped mostly by lipid bilayer viscosity.
pubmed:grant
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-1059096, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-1191685, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-1279177, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-1382186, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-1703449, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-1712238, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-1715999, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-1717016, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-2081267, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-2215695, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-236202, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-2410044, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-2412602, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-2423148, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-2447968, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-2447969, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-2449693, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-3023396, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-3179296, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-396781, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-4429725, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-4429726, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-4461846, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-4475108, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-4509315, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-5044577, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-6258181, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-6270629, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-6331286, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-6351724, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-7025092, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-7115881, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-73138, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-7354837, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-7518571, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-7680310, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-7689461, http://linkedlifedata.com/resource/pubmed/commentcorrection/8599640-952910
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0006-3495
pubmed:author
pubmed:issnType
Print
pubmed:volume
69
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2337-49
pubmed:dateRevised
2009-11-18
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
Molecular dynamics of alamethicin transmembrane channels from open-channel current noise analysis.
pubmed:affiliation
Physics Department, Cornell University, Ithaca, New York 14853, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.