Linked Life Data

11916412

Source:http://linkedlifedata.com/resource/pubmed/id/11916412

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
13
pubmed:dateCreated
2002-3-27
pubmed:abstractText
Cation-pi interactions are increasingly recognized as important in chemistry and biology. Here we investigate the cation-pi interaction by determining its effect on the helicity of model peptides using a combination of CD and NMR spectroscopy. The data show that a single Trp/Arg interaction on the surface of a peptide can make a significant net favorable free energy contribution to helix stability if the two residues are positioned with appropriate spacing and orientation. The solvent-exposed Trp-->Arg (i, i + 4) interaction in helices can contribute -0.4 kcal/mol to the helix stability, while no free energy gain is detected if the two residues have the reversed orientation, Arg-->Trp (i, i + 4). The derived free energy is consistent with other experimental results studied in proteins or model peptides on cation-pi interactions. However in the same system the postulated Phe/Arg (i, i + 4) cation-pi interaction provides no net free energy to helix stability. Thus the Trp-->Arg interaction is stronger than Phe-->Arg. The cation-pi interactions are not sensitive to the screening effect by adding neutral salt as indicated by salt titration. Our results are in qualitative agreement with theoretical calculations emphasizing that cation-pi interactions can contribute significantly to protein stability with the order Trp > Phe. However, our and other experimental values are significantly smaller than estimates from theoretical calculations.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0002-7863
pubmed:author
pubmed:issnType
Print
pubmed:day
3
pubmed:volume
124
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3284-91
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Cation-pi interaction in model alpha-helical peptides.
pubmed:affiliation
Department of Chemistry, New York University, New York 10003, USA.
pubmed:publicationType
Journal Article