Linked Life Data

12175233

Source:http://linkedlifedata.com/resource/pubmed/id/12175233

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
33
pubmed:dateCreated
2002-8-14
pubmed:abstractText
The influence of natural and unnatural i, i + 4 aromatic side chain-side chain interactions on alpha-helix stability was determined in Ala-Lys host peptides by circular dichroism (CD). All interactions investigated provided some stability to the helix; however, phenylalanine-phenylalanine (F-F) and phenylalanine-pentafluorophenylalanine (F-f5F) interactions resulted in the greatest enhancement in helicity, doubling the helical content over i, i + 5 control peptides at internal positions. Quantification of these interactions using AGADIR multistate helix-coil algorithm revealed that the F-F and F-f5F interaction energies are equivalent at internal positions in the sequence (deltaGF-F = deltaGF-f5F = -0.27 kcal/mol), despite the differences in their expected geometries. As the strength of a face-to-face stacked phenyl-pentafluorophenyl interaction should surpass an edge-to-face or offset-stacked phenyl-phenyl interaction, we believe this result reflects the inability of the side chains in F-f5F to attain a fully stacked geometry within the context of an alpha-helix. Positioning the interactions at the C-terminus led to much stronger interactions (deltaGF-F = -0.8 kcal/mol; deltaGF-f5F = -0.55 kcal/mol) likely because of favorable chi(1) rotameric preferences for aromatic residues at C-capping regions of alpha-helices, suggesting that aromatic side chain-side chain interactions are an effective alpha-helix C-capping method.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0002-7863
pubmed:author
pubmed:issnType
Print
pubmed:day
21
pubmed:volume
124
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9751-5
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Contribution of aromatic interactions to alpha-helix stability.
pubmed:affiliation
Department of Chemistry, UNC Chapel Hill, Venable and Kenan Laboratories, CB 3290, Chapel Hill, North Carolina 27599, USA.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't