The metal ion binding properties of two fluorescent analogues of trichogin GA IV, which is a natural undecapeptide showing significant antimicrobial activity, were studied by circular dichroism, time-resolved optical spectroscopy, and molecular mechanics calculations. Binding of Ca(II) and Gd(III) to the peptides investigated was shown to promote a structural transition from highly helical conformations to folded structures characterized by formation of a loop that embedded the metal ion. Time-resolved spectroscopy revealed that peptide dynamics is also remarkably affected by ion binding: peptide-backbone motions slowed down to the microsecond time scale. Finally, molecular mechanics calculations emphasized the role of the central Gly5-Gly6 motif, which allowed for the twisting of the peptide segment that gave rise to the formation of the binding cavity.
Venanzi, M., Bocchinfuso, G., Gatto, E., Palleschi, A., Stella, L., Formaggio, F., et al. (2009). Metal binding properties of fluorescent analogues of trichogin GA IV: a conformational study by time-resolved spectroscopy and molecular mechanics investigations. CHEMBIOCHEM, 10(1), 91-97 [10.1002/cbic.200800617].
Metal binding properties of fluorescent analogues of trichogin GA IV: a conformational study by time-resolved spectroscopy and molecular mechanics investigations
VENANZI, MARIANO;BOCCHINFUSO, GIANFRANCO;GATTO, EMANUELA;PALLESCHI, ANTONIO;STELLA, LORENZO;
2009-01-05
Abstract
The metal ion binding properties of two fluorescent analogues of trichogin GA IV, which is a natural undecapeptide showing significant antimicrobial activity, were studied by circular dichroism, time-resolved optical spectroscopy, and molecular mechanics calculations. Binding of Ca(II) and Gd(III) to the peptides investigated was shown to promote a structural transition from highly helical conformations to folded structures characterized by formation of a loop that embedded the metal ion. Time-resolved spectroscopy revealed that peptide dynamics is also remarkably affected by ion binding: peptide-backbone motions slowed down to the microsecond time scale. Finally, molecular mechanics calculations emphasized the role of the central Gly5-Gly6 motif, which allowed for the twisting of the peptide segment that gave rise to the formation of the binding cavity.Questo articolo è pubblicato sotto una Licenza Licenza Creative Commons
