title: Ca(2+) -complex stability of GAPAGPLIVPY peptide in gas and aqueous phase, investigated by affinity capillary electrophoresis and molecular dynamics simulations and compared to mass spectrometric results.
abstract: Strong, sequence-specific gas-phase bindings between proline-rich peptides and alkaline earth metal ions in nanoESI-MS experiments were reported by Lehmann et al. (Rapid Commun. Mass Spectrom. 2006, 20, 2404-2410), however its relevance for physiological-like aqueous phase is uncertain. Therefore, the complexes should also be studied in aqueous solution and the relevance of the MS method for binding studies be evaluated. A mobility shift ACE method was used for determining the binding between the small peptide GAPAGPLIVPY and various metal ions in aqueous solution. The findings were compared to the MS results and further explained using computational methods. While the MS data showed a strong alkaline earth ion binding, the ACE results showed nonsignificant binding. The proposed vacuum state complex also decomposed during a molecular dynamic simulation in aqueous solution. This study shows that the formed stable peptide-metal ion adducts in the gas phase by ESI-MS does not imply the existence of analogous adducts in the aqueous phase. Comparing peptide-metal ion interaction under the gaseous MS and aqueous ACE conditions showed huge difference in binding behavior.
authors.affiliation: Institute of Medicinal and Pharmaceutical Chemistry, TU Braunschweig, Braunschweig, Germany.
authors.forename: Markus
authors.initials: M
authors.lastname: Nachbar
authors.affiliation: Institute of Medicinal and Pharmaceutical Chemistry, TU Braunschweig, Braunschweig, Germany.
authors.forename: Sami
authors.initials: S
authors.lastname: El Deeb
authors.affiliation: Institute of Medicinal and Pharmaceutical Chemistry, TU Braunschweig, Braunschweig, Germany.
authors.forename: Mona
authors.initials: M
authors.lastname: Mozafari
authors.affiliation: Institute of Medicinal and Pharmaceutical Chemistry, TU Braunschweig, Braunschweig, Germany.
authors.forename: Hassan A
authors.initials: HA
authors.lastname: Alhazmi
authors.affiliation: Institute of Medicinal and Pharmaceutical Chemistry, TU Braunschweig, Braunschweig, Germany.
authors.forename: Lutz
authors.initials: L
authors.lastname: Preu
authors.affiliation: Institute of Medicinal and Pharmaceutical Chemistry, TU Braunschweig, Braunschweig, Germany.
authors.forename: Sabine
authors.initials: S
authors.lastname: Redweik
authors.affiliation: Core Facility Molecular Structure Analysis, German Cancer Research Center (DKFZ), Heidelberg, Germany.
authors.forename: Wolf Dieter
authors.initials: WD
authors.lastname: Lehmann
authors.affiliation: Institute of Medicinal and Pharmaceutical Chemistry, TU Braunschweig, Braunschweig, Germany.
authors.forename: Hermann
authors.initials: H
authors.lastname: Wätzig
mesh_terms: D002118:Calcium / Q000737:chemistry*; D019075:Electrophoresis, Capillary / Q000379:methods*; D005740:Gases / Q000737:chemistry*; D013058:Mass Spectrometry; D056004:Molecular Dynamics Simulation; D010455:Peptides / Q000737:chemistry*
chemical_list: D005740:Gases; D010455:Peptides; D002118:Calcium
keywords: Affinity capillary electrophoresis; Galectin-3; Metalloproteomics