CuII coordination chemistry of patellamide derivatives

• Verfasst von: Comba, Peter [VerfasserIn]
• Verfasst von: Dovalil, Nina [VerfasserIn]
• Verfasst von: Seibold, Björn [VerfasserIn]
• Verfasst von: Vadivelu, Prabha [VerfasserIn]
• Titel: CuII coordination chemistry of patellamide derivatives
• Titelzusatz: possible biological functions of cyclic pseudopeptides
• Verf.angabe: Peter Comba, Nina Dovalil, Lawrence R. Gahan, Gebhard Haberhauer, Graeme R. Hanson, Christopher J. Noble, Björn Seibold and Prabha Vadivelu
• E-Jahr: 2012
• Jahr: 20 January 2012
• Umfang: 13 S.
• Fussnoten: Im Titel sind die II in CuII hochgestellt ; Gesehen am 22.08.2018
• Titel Quelle: Enthalten in: Chemistry - a European journal
• Ort Quelle: Weinheim : Wiley-VCH, 1995
• Jahr Quelle: 2012
• Band/Heft Quelle: 18(2012), 9, Seite 2578-2590
• ISSN Quelle: 1521-3765
• DOI: doi:10.1002/chem.201101975
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: CO2 fixation
• Sach-SW: copper coordination chemistry
• Sach-SW: cyclic peptides
• Sach-SW: EPR spectroscopy
• Sach-SW: molecular modeling
• K10plus-PPN: 1580266029

Abstract

Two synthetic derivatives of the naturally occurring cyclic pseudooctapeptides patellamide A-F and ascidiacyclamide, that is, H4pat2, H4pat3, as well as their CuII complexes are described. These cyclic peptide derivatives differ from the naturally occurring macrocycles by the variation of the incorporated heterocyclic donor groups and the configuration of the amino acids connecting the heterocycles. The exchange of the oxazoline and thiazole groups by dimethylimidazoles or methyloxazoles leads to more rigid macrocycles, and the changes in the configuration of the side chains leads to significant differences in the folding of the cyclic peptides. These variations allow a detailed study of the various possible structural changes on the chemistry of the CuII complexes formed. The coordination of CuII with these macrocyclic species was monitored by high-resolution electrospray mass spectrometry (ESI-MS), spectrophotometric (UV/Vis) and circular dichroic (CD) titrations, and electron paramagnetic resonance (EPR) spectroscopy. Density functional theory (DFT) calculations and molecular mechanics (MM) simulations have been used to model the structures of the CuII complexes and provide a detailed understanding of their geometric preferences and conformational flexibility. This is related to the CuII coordination chemistry and the reactivity of the dinuclear CuII complexes towards CO2 fixation. The variation observed between the natural and various synthetic peptide systems enables conclusions about structure-reactivity correlations, and our results also provide information on why nature might have chosen oxazolines and thiazoles as incorporated heterocycles.