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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
45
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pubmed:dateCreated |
1993-12-21
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pubmed:abstractText |
Ala-based peptides form marginally stable helices at low temperature and are conventionally considered as mixtures of alpha-helix and random coil. However, recent work with doubly spin-labeled peptides suggests that short 16-residue sequences contain a significant fraction of 3(10)-helix near the N-terminus (positions 4-8). Using the same double-label strategy, we report on the helix geometry of the peptides Ac-(AAAAK)nA-NH2 with n = 3 and n = 4. The 16-mer (n = 3) is now examined at a region near the C-terminus, and there is evidence for 3(10)-helix here as well. The 21-mer (n = 4) is examined in three regions of the sequence. In dramatic contrast to the 16-mer, the 21-mer exhibits the signature of alpha-helix at the N-terminus and on through the middle of the peptide. The 21-mer C-terminus, however, adopts the 3(10)-helix geometry as is often found for C-termini in protein alpha-helices. These data indicate that the proportion of alpha-helix and 3(10)-helix in Ala-based peptides depends upon the sequence length.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Nov
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pubmed:issn |
0006-2960
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:day |
16
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pubmed:volume |
32
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pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
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pubmed:pagination |
11957-62
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:8218270-Alanine,
pubmed-meshheading:8218270-Amino Acid Sequence,
pubmed-meshheading:8218270-Circular Dichroism,
pubmed-meshheading:8218270-Electron Spin Resonance Spectroscopy,
pubmed-meshheading:8218270-Molecular Sequence Data,
pubmed-meshheading:8218270-Peptides,
pubmed-meshheading:8218270-Protein Conformation,
pubmed-meshheading:8218270-Spectrophotometry, Ultraviolet
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pubmed:year |
1993
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pubmed:articleTitle |
Increasing sequence length favors alpha-helix over 3(10)-helix in alanine-based peptides: evidence for a length-dependent structural transition.
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pubmed:affiliation |
Department of Chemistry and Biochemistry, University of California, Santa Cruz 95064.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.,
Research Support, U.S. Gov't, Non-P.H.S.,
Research Support, Non-U.S. Gov't
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