Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2001-3-14
pubmed:abstractText
The isolated D2 domain of annexin I is unable to adopt a tertiary fold but exhibits both native and non-native residual structures. It thus constitutes an attractive model for the investigation of dynamics of partially folded states in the context of protein folding and stability. 15N relaxation parameters of the D2 domain have been acquired at three different magnetic fields, 500, 600 and 800 MHz. This enables the estimation of the contribution of conformational exchange to the relaxation parameters on the micro- to millisecond time scale, thus providing a suitable data set for the description of motions on the pico- and nanosecond time scale. The analysis of the seven spectral densities obtained (J(0), J(50 MHz), J(60 MHz), J(80 MHz), <J(500 MHz)>, <J(600 MHz)>, <J(800 MHz)>) provides complementary and meaningful results on the conformational features of the D2 domain structure previously depicted by chemical shift and NOE data. Especially, residual helix segments exhibit distinct dynamical behaviors that are related to their intrinsic helical propensity. Beside the spectral density analysis, a series of models derived from the Lipari and Szabo model-free approach are investigated. Two models containing three parameters are able to reproduce equally well the experimental data within experimental errors but provide different values of order parameters and correlation times. The inability to find a unique model to describe the data emphasizes the difficulty to use and interpret the model-free parameters in the case of partially or fully unfolded proteins consisting of a wide range of interconverting conformers.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0925-2738
pubmed:author
pubmed:issnType
Print
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3-18
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
15N NMR relaxation as a probe for helical intrinsic propensity: the case of the unfolded D2 domain of annexin I.
pubmed:affiliation
CNRS, Institut de Chimie des Substances Naturelles, Gif sur Yvette, France.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't