Linked Life Data

16387780

Source:http://linkedlifedata.com/resource/pubmed/id/16387780

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2006-3-2
pubmed:abstractText
Combining an azobenzene chromophore with the bis-cysteinyl active-site sequence of the protein disulfide isomerase (PDI) we constructed a simple but promising model for allosteric conformational rearrangements. Paralleling cellular signaling events, an external trigger, here absorption of a photon, leads to a structural change in one part of the molecule, namely the azobenzene-based chromophore. The change in geometry translates to the effector site, in our case the peptide sequence, where it modifies covalent and nonbonded interactions and thus leads to a conformational rearrangement. NMR spectroscopy showed that the trans-azo and cis-azo isomer of the cyclic PDI peptide exhibit different, but well-defined structures when the two cystine residues form a disulfide bridge. Without this intramolecular cross-link conformationally more variable structural ensembles are obtained that again differ for the two isomeric states. Ultrafast UV/Vis spectroscopy confirmed that the rapid isomerization of azobenzene is not significantly slowed down when incorporated into the cyclic peptides, although the amplitudes of ballistic and diffusive pathways are changed. The observation that most of the energy of an absorbed photon is dissipated to the solvent in the first few picoseconds when the actual azo-isomerization takes place is important. The conformational rearrangement is weakly driven due to the absence of appreciable excess energy and can be described as biased diffusion similar to natural processes.
pubmed:commentsCorrections
http://linkedlifedata.com/resource/pubmed/commentcorrection/16387780-10587315, http://linkedlifedata.com/resource/pubmed/commentcorrection/16387780-10984401, http://linkedlifedata.com/resource/pubmed/commentcorrection/16387780-10984402, http://linkedlifedata.com/resource/pubmed/commentcorrection/16387780-11920439, http://linkedlifedata.com/resource/pubmed/commentcorrection/16387780-12060746, http://linkedlifedata.com/resource/pubmed/commentcorrection/16387780-12563307, http://linkedlifedata.com/resource/pubmed/commentcorrection/16387780-12736378, http://linkedlifedata.com/resource/pubmed/commentcorrection/16387780-15041673, http://linkedlifedata.com/resource/pubmed/commentcorrection/16387780-15637699, http://linkedlifedata.com/resource/pubmed/commentcorrection/16387780-15779909, http://linkedlifedata.com/resource/pubmed/commentcorrection/16387780-6661238
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0006-3495
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
90
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
2099-108
pubmed:dateRevised
2010-9-20
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
A conformational two-state peptide model system containing an ultrafast but soft light switch.
pubmed:affiliation
Max-Planck-Institut für Biochemie, 82152 Martinsried, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't