Linked Life Data

7514039

Source:http://linkedlifedata.com/resource/pubmed/id/7514039

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
1994-6-16
pubmed:abstractText
The backbone dynamics of the C-terminal SH2 domain of phospholipase C gamma 1 have been investigated. Two forms of the domain were studied, one in complex with a high-affinity binding peptide derived from the platelet-derived growth factor receptor and the other in the absence of this peptide. 2-D 1H-15N NMR methods, employing pulsed field gradients, were used to determine steady-state 1H-15N NOE values and T1 and T2 15N relaxation times. Backbone dynamics were characterized by the overall correlation time (tau m), order parameters (S2), effective correlation times for internal motions (tau e), and, if required, terms to account for motions on a microsecond-to-millisecond-time scale. An extended two-time-scale formalism was used for residues having relaxation data and that could not be fit adequately using a single-time-scale formalism. The overall correlation times of the uncomplexed and complexed forms of SH2 were found to be 9.2 and 6.5 ns, respectively, suggesting that the uncomplexed form is in a monomer-dimer equilibrium. This was subsequently confirmed by hydrodynamic measurements. Analysis of order parameters reveals that residues in the so-called phosphotyrosine-binding loop exhibited higher than average disorder in both forms of SH2. Although localized differences in order parameters were observed between the uncomplexed and complexed forms of SH2, overall, higher order parameters were not found in the peptide-bound form, indicating that on average, picosecond-time-scale disorder is not reduced upon binding peptide. The relaxation data of the SH2-phosphopeptide complex were fit with fewer exchange terms than the uncomplexed form. This may reflect the monomer-dimer equilibrium that exists in the uncomplexed form or may indicate that the complexed form has lower conformational flexibility on a microsecond-to-millisecond-time scale.
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
17
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5984-6003
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Backbone dynamics of a free and phosphopeptide-complexed Src homology 2 domain studied by 15N NMR relaxation.
pubmed:affiliation
Protein Engineering Network Centres of Excellence, University of Toronto, Ontario, Canada.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't