title: Strength and character of peptide/anion interactions.
abstract: The binding free energy of complex [Co(C(2)O(4))(3)](3-) to three peptides H-Lys-Gly-Lys-Gly-Lys-Gly-Lys-NH(2) (P-1), H-(Lys-Gly-Lys-Gly-Lys-Gly-Lys)(2)-NH(2) (P-2), H-(Lys-Gly-Lys-Gly-Lys-Gly-Lys)(3)-NH(2) (P-3) and to the monomers (amino acids) forming the peptides has been obtained using the kinetics of the electron-transfer reaction between [Ru(NH(3))(5)py](2+) and [Co(C(2)O(4))(3)](3-) as the probe. The polymerization of the monomers increases the negative free energy of binding and changes its character, noncooperative for the monomers and anticooperative for the peptides. This increase in the negative free energy represents a driving force for the polymerization process. The magnitude of the gain in negative free energy, as a consequence of the anticooperative character of the binding of the cobalt complex to the peptide, depends on the ratio of [complex]/[monomers].
authors.affiliation: Centre de Biochemie Structurale CNRS UMR 5048 INSERM UMR 554, Université de Montpellier 1 29, route de Navacelles 34090 Montpellier Cedex, France.
authors.forename: A
authors.initials: A
authors.lastname: Chavanieu
authors.forename: J F
authors.initials: JF
authors.lastname: Guichou
authors.forename: R
authors.initials: R
authors.lastname: Prado-Gotor
authors.forename: P
authors.initials: P
authors.lastname: Perez-Tejeda
authors.forename: R
authors.initials: R
authors.lastname: Jimenez
authors.forename: P
authors.initials: P
authors.lastname: Lopez-Cornejo
authors.forename: F
authors.initials: F
authors.lastname: Sanchez
mesh_terms: D000596:Amino Acids / Q000737:chemistry; D000838:Anions / Q000737:chemistry; D004735:Energy Transfer; D007202:Indicators and Reagents; D007700:Kinetics; D009682:Magnetic Resonance Spectroscopy; D010455:Peptides / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry
chemical_list: D000596:Amino Acids; D000838:Anions; D007202:Indicators and Reagents; D010455:Peptides; D011108:Polymers