title: Small interacting peptides. Part I. Interaction of cyclohexapeptides with an unspecific SiOH surface: comparison of infrared investigations and force field calculations.
abstract: The interaction of cyclohexapeptides c(X(1)(1)K(2)X(2)(3)K(4)X(3)(5)K(6)) in water with hydrolysed silicon surfaces were studied by attenuated total reflection Fourier transform infrared (ATR FTIR) spectroscopy and by force field calculations. The band sequences (1800-1500 cm(-1)) for dissolved and adsorbed cyclohexapeptides were recorded and compared with those obtained after flushing with distilled water in order to eliminate the background signal of the peptides in solution. Band analyses and principal component analyses were carried out for the characteristic peptide vibrations in order to evaluate the spectra. In addition, force field calculations were performed to study the binding energies to the surface and to illustrate the possible structures of the cyclohexapeptides. The positively charged lysine side chains of the cyclohexapeptides interact with the OH groups of the surface, as indicated by band shifts. This also was verified by the force field calculations. The bonding stability increases with the number of interacting sites (lysine side chains and other peptide residues) to the surface. These sites are determined by structure and polarity of the cyclohexapeptides.
authors.affiliation: Institute of Physical and Theoretical Chemistry, University of Tübingen, Auf der Morgenstelle 8, D-72076 Tübingen, Germany.
authors.forename: Frauke
authors.initials: F
authors.lastname: Palmer
authors.forename: Christiane
authors.initials: C
authors.lastname: Stingel
authors.forename: Rolf
authors.initials: R
authors.lastname: Tünnemann
authors.forename: Hans-Georg
authors.initials: HG
authors.lastname: Mack
authors.forename: Günther
authors.initials: G
authors.lastname: Jung
authors.forename: Volker
authors.initials: V
authors.lastname: Hoffmann
mesh_terms: D001665:Binding Sites; D008239:Lysine / Q000737:chemistry; D008958:Models, Molecular; D010452:Peptide Biosynthesis; D010455:Peptides / Q000737:chemistry*; D012821:Silanes / Q000032:analysis / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared / Q000295:instrumentation / Q000379:methods
chemical_list: D010455:Peptides; D012821:Silanes; C082343:silanol; D008239:Lysine