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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
9
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pubmed:dateCreated |
1999-1-12
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pubmed:abstractText |
Covalent crosslinks can control local peptide conformation. In tripeptide sequences of the general formula Cys-Xxx-Cys, cysteine disulfides have been previously shown to enforce a C7 equatorial gamma-turn conformation (also referred to as an inverse gamma-turn). Much less is known about the effects of dityrosine and ditryptophan crosslinks on local peptide structure. In a series of tripeptides, ditryptophan crosslinks were formed using the two-step process of acid-promoted Mannich dimerization followed by oxidative aromatization. In these peptides, with the general formula Trp-Xxx-Trp (Xxx not equal to Gly), ditryptophan crosslinks were found to stabilize a C7 equatorial gamma-turn conformation in DMSO-d6. Rigorous support for a C7 equatorial conformation in the crosslinked sequence Trp-Pro-Trp came from a variety of 1H NMR experiments and molecular modelling. Interproton distances were derived from NOE buildups that were determined through a series of double pulsed field gradient spin echo (DPFGSE) experiments. In addition, the small temperature dependence of the i+2 NH chemical shifts (delta delta/delta T < 2 ppm/degree C) provided further support for the intramolecular hydrogen bond which defines a gamma-turn.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Sep
|
pubmed:issn |
0968-0896
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
6
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
1439-46
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pubmed:dateRevised |
2011-1-24
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pubmed:meshHeading |
pubmed-meshheading:9801815-Cross-Linking Reagents,
pubmed-meshheading:9801815-Dimethyl Sulfoxide,
pubmed-meshheading:9801815-Dipeptides,
pubmed-meshheading:9801815-Models, Molecular,
pubmed-meshheading:9801815-Spectrum Analysis,
pubmed-meshheading:9801815-Temperature,
pubmed-meshheading:9801815-Tryptophan
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pubmed:year |
1998
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pubmed:articleTitle |
Stabilization of a C7 equatorial gamma turn in DMSO-d6 by a ditryptophan crosslink.
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pubmed:affiliation |
Department of Chemistry, University of California-Irvine 92697-2025, USA.
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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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