Linked Life Data

15688655

Source:http://linkedlifedata.com/resource/pubmed/id/15688655

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
2005-2-3
pubmed:abstractText
To understand the intrinsic properties of peptides, which are determined by factors such as intramolecular hydrogen bonding, van der Waals bonding and electrostatic interactions, the conformational landscape of isolated protein building blocks in the gas phase was investigated. Here, we present IR-UV double-resonance spectra of jet-cooled, uncapped peptides containing a tryptophan (Trp) UV chromophore in the 1000-2000 cm(-1) spectral range. In the series Trp, Trp-Gly and Trp-Gly-Gly (where Gly stands for glycine), the number of detected conformers was found to decrease from six (Snoek et al., PCCP, 2001, 3, 1819) to four and two, respectively, which indicates a trend to relaxation to a global minimum. Density functional theory calculations reveal that the O-H in-plane bending vibration, together with the N-H in-plane bend ing and the peptide C=O stretching vibrations, is a sensitive probe to hydrogen bonding and, thus, to the folding of the peptide backbone in these structures. This enables the identification of spectroscopic fingerprints for the various conformational structures. By comparing the experimentally observed IR spectra with the calculated spectra, a unique conformational assignment can be made in most cases. The IR-UV spectrum of a Trp-containing nonapeptide (Trp-Ala-Gly-Gly-Asp-Ala-Ser-Gly-Glu) was recorded as well and, although the IR spectrum is less well-resolved (and it probably results from different isomers), groups of amide I (peptide C=O stretching) and amide II (N-H in-plane bending) bands can still be recognised, in agreement with predictions at the AM1 level.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
1439-4235
pubmed:author
pubmed:issnType
Print
pubmed:volume
6
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
120-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Folding structures of isolated peptides as revealed by gas-phase mid-infrared spectroscopy.
pubmed:affiliation
FOM Institute for Plasma Physics Rijnhuizen, Edisonbaan 14, 3439 MN Nieuwegein, The Netherlands. jmbakker@fhi-berlin.mpg.de
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't