Premium
Photocontrol of the Collagen Triple Helix: Synthesis and Conformational Characterization of Bis‐cysteinyl Collagenous Peptides with an Azobenzene Clamp
Author(s) -
Kusebauch Ulrike,
Cadamuro Sergio A.,
Musiol HansJürgen,
Moroder Luis,
Renner Christian
Publication year - 2007
Publication title -
chemistry – a european journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.687
H-Index - 242
eISSN - 1521-3765
pISSN - 0947-6539
DOI - 10.1002/chem.200601162
Subject(s) - azobenzene , triple helix , chemistry , helix (gastropod) , biophysics , stereochemistry , biology , molecule , organic chemistry , ecology , snail
For the photomodulation of the collagen triple helix with an azobenzene clamp, we investigated various collagenous peptides consisting of ideal (Gly‐Pro‐Hyp) repeats and containing cysteine residues in various positions for a side chain‐to‐side chain crosslink with a suitable chromophore derivative. Comparative conformational analysis of these cysteine peptides indicated an undecarepeat peptide with two cysteine residues located in the central portion in i and i+7 positions and flanked by (Gly‐Pro‐Hyp) repeat sequences as the most promising for the cross‐bridging experiments. In aqueous alcoholic solution the azobenzene–undecarepeat peptide formed a stable triple helix in equilibrium with the monomeric species as a trans ‐azobenzene isomer, whereas photoisomerization to the cis isomer leads to unfolding of at least part of the triple helix. Furthermore, the residual supercoiled structure acts like an intermolecular knot, thus making refolding upon cis ‐to‐ trans isomerization a concentration‐independent fast event. Consequently, these photoswitchable collagenous systems should be well suited for time‐resolved studies of folding/unfolding of the collagen triple helix under variable thermodynamic equilibria.