Linked Life Data

9779786

Source:http://linkedlifedata.com/resource/pubmed/id/9779786

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1998-12-18
pubmed:abstractText
The model peptide XAAAAEAAARAAAARamide is used to examine the contributions of an N-terminal capping interaction to the conformation and stability of a helical ensemble. The reference peptide has an alanine residue at position X while the capping peptide has a serine residue at this position. The helical ensemble was characterized using circular dichroism measurements and carbonyl-carbon chemical shift measurements of selectively enriched residues. The distribution of helicity within the ensemble of the reference peptide at pH 11 and 0 degrees C appears symmetrical, having a uniform central helix and frayed ends. This distribution is truncated at pH 6 by the repulsive electrostatic interaction between the positively charged alpha-amino group and the positively charged end of the helical macrodipole. The capping peptide forms a side-chain/ main-chain hydrogen bond involving the serine residue and amide of alanine 4. The presence of this hydrogen bond generates a unique motif in the chemical shift profile of its helical ensemble. The conformational stabilization contributed by this hydrogen bond, although cooperatively distributed throughout the helical ensemble, is preferentially focused within the first helical turn. The stabilization provided by this hydrogen bond is able to offset the truncation of the helical ensemble generated by the repulsive electrostatic interaction observed at pH 6.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0887-3585
pubmed:author
pubmed:issnType
Print
pubmed:day
1
pubmed:volume
33
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
167-76
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Analysis of N-terminal capping using carbonyl-carbon chemical shift measurements.
pubmed:affiliation
Department of Biochemistry, University of Iowa, Iowa City 52242, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't