Linked Life Data

10968972

Source:http://linkedlifedata.com/resource/pubmed/id/10968972

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2000-10-25
pubmed:abstractText
NMR relaxation-derived spectral densities provide information on molecular and internal motions occurring on the picosecond to nanosecond time scales. Using (13)C and (15)N NMR relaxation parameters [T(1), T(2), and NOE] acquired at four Larmor frequencies (for (13)C: 62.5, 125, 150, and 200 MHz), spectral densities J(0), J(omega(C)), J(omega(H)), J(omega(H) + omega(C)), J(omega(H) - omega(C)), J(omega(N)), J(omega(H) + omega(N)), and J(omega(H) - omega(N)) were derived as a function of frequency for (15)NH, (13)C(alpha)H, and (13)C(beta)H(3) groups of an alanine residue in an alpha-helix-forming peptide. This extensive relaxation data set has allowed derivation of highly defined (13)C and (15)N spectral density maps. Using Monte Carlo minimization, these maps were fit to a spectral density function of three Lorentzian terms having six motional parameters: tau(0), tau(1), tau(2), c(0), c(1), and c(2), where tau(0), tau(1) and tau(2) are correlation times for overall tumbling and for slower and faster internal motions, and c(0), c(1), and c(2) are their weighting coefficients. Analysis of the high-frequency portion of these maps was particularly informative, especially when deriving motional parameters of the side-chain methyl group for which the order parameter is very small and overall tumbling motions do not dominate the spectral density function. Overall correlation times, tau(0), are found to be in nanosecond range, consistent with values determined using the Lipari-Szabo model-free approach. Internal motional correlation times range from picoseconds for methyl group rotation to nanoseconds for backbone N-H, C(alpha)-H, and C(alpha)-C(beta) bond motions. General application of this approach will allow greater insight into the internal motions in peptides and proteins.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1090-7807
pubmed:author
pubmed:copyrightInfo
Copyright 2000 Academic Press.
pubmed:issnType
Print
pubmed:volume
146
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
188-95
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2000
pubmed:articleTitle
Peptide internal motions on nanosecond time scale derived from direct fitting of (13)C and (15)N NMR spectral density functions.
pubmed:affiliation
Department of Biochemistry, Molecular Biology, and Biophysics, Biomedical Engineering Center, University of Minnesota Health Science Center, 6-155 Jackson Hall, Minneapolis, Minnesota 55455, USA. mayox001@maroon.tc.umn.edu
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.