Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
9
pubmed:dateCreated
1999-1-12
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.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0968-0896
pubmed:author
pubmed:issnType
Print
pubmed:volume
6
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1439-46
pubmed:dateRevised
2011-1-24
pubmed:meshHeading
pubmed:year
1998
pubmed:articleTitle
Stabilization of a C7 equatorial gamma turn in DMSO-d6 by a ditryptophan crosslink.
pubmed:affiliation
Department of Chemistry, University of California-Irvine 92697-2025, USA.
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