Linked Life Data

7772415

Source:http://linkedlifedata.com/resource/pubmed/id/7772415

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1995-7-12
pubmed:abstractText
Fourier transform infrared (FTIR) spectroscopy has been used to explore the thermal unfolding of three helical, alanine-based peptides. Each of the peptides follows the general sequence Ac-(AAAX)nA-NH2 where X is either Lys+ or Arg+ and n = 3 or 4. These particular peptides were chosen because they contain varying amounts of 3(10)- and alpha-helix. The amide I' bands for all three peptides, under helix forming conditions, are between 1632 and 1635 cm-1. These results are incongruous with the assignment for alpha-helices in proteins where amide I' bands are usually found above 1650 cm-1. At elevated temperatures, all the peptides exhibit amide I' bands of 1642 cm-1, which is the accepted value for random coil. Variable temperature spectra for the 4K peptide (n = 4, X = Lys+), which is the most alpha-helical of the three peptides at 1 degree C, reveal an isosbestic point suggesting a cooperative two-state unfolding transition. The other peptides, however, did not reveal an isosbestic point, thereby indicating the presence of an intermediate, perhaps 3(10)-helix, along the thermal unfolding pathway.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1047-8477
pubmed:author
pubmed:issnType
Print
pubmed:volume
114
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
23-7
pubmed:dateRevised
2008-11-21
pubmed:meshHeading
pubmed:articleTitle
FTIR spectroscopy of alanine-based peptides: assignment of the amide I' modes for random coil and helix.
pubmed:affiliation
Department of Chemistry and Biochemistry, University of California, Santa Cruz 95064, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.