Linked Life Data

17193192

Source:http://linkedlifedata.com/resource/pubmed/id/17193192

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
8
pubmed:dateCreated
2006-12-28
pubmed:abstractText
We report the investigation of two 16-residue peptides in aqueous solution by means of molecular-dynamics simulations. The peptides constitute the C- and N-terminal halves of the 33-residue monomer whose dimer constitutes the leucine zipper of the yeast transcriptional activator, denoted GCN4-p1. To examine a hypothesis about coiled-coil formation, in which the C-terminal half contains a helix-formation trigger site absent in the N-terminal half, experimental studies of the two peptides have determined their helix propensities under several conditions of temperature, pH, and salt concentration with circular dichroism. An NMR experiment provides additional evidence. At temperatures of 278 and 325 K and pH 7.5, mixtures of alpha- and pi-helical secondary structure constitute the most probable conformations in both C- and N-terminal halves. A bifurcated salt bridge between Arg25 and Glu22/20 correlates with the structural fluctuations of the C-terminal half. It also exhibits a persistent loop at the N-terminal end involving the side chains of His18 and Glu22, which is reminiscent of helix-capping boxes. Nonreversible unfolding appears to occur abruptly in the Arg25 mutant, suggesting a cooperative event. Analysis does not indicate that the N-terminal half is less stable than the C-terminal half, indicating that 100 ns is too short a period to observe complete unfolding.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
1612-1880
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
2
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1086-104
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Molecular-dynamics simulations of C- and N-terminal peptide derivatives of GCN4-p1 in aqueous solution.
pubmed:affiliation
Biomolecular Research, Paul Scherrer Institut, CH-5232 Villigen. john.missimer@psi.ch
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't