Copper(II) binding modes in the prion octapeptide PHGGGWGQ: A spectroscopic and voltammetric study(566 views) Bonomo RP, Imperllizzeri G, Pappalardo G, Rizzarelli E, Tabbì G
Chemistry (ISSN: 0947-6539, 1521-3765, 1521-3765electronic), 2000 Nov 17; 6(22): 4195-4202.
Affiliations: Dipartimento di Scienze Chimiche, Università di Catania, V.Le A. Doria 6, 95125 Catania, Italy
Ist. Stud. Sostanze Naturali I., Sezione Stud. Modelli Metallo E., V.Le A. Doria 6, 95125 Catania, Italy
References: Not available.
Copper(II) binding modes in the prion octapeptide PHGGGWGQ: A spectroscopic and voltammetric study
The N-terminal octapeptide repeat region of human prion protein (PrPc) is known to bind CuII. To investigate the binding modes of copper in PrPc, an octapeptide Ac-PHGGGWGQ-NH2 (1), which corresponds to an octarepeat sequence, and a tetrapeptide Ac-HGGG-NH2 (2) have been synthesised. The copper(II) complexes formed with 1 and 2 have been studied by circular dichroism (CD) and electron spin resonance (ESR) spectroscopy. Both peptides form 1:1 complexes with CuII at neutral and basic pH. CD, ESR and visible absorption spectra suggest a similar co-ordination sphere of the metal ion in both peptides, which at neutral pH consists of a square pyramidal geometry with three peptidic nitrogens and the imidazole nitrogen as donor atoms. Cyclic voltammetric measurements were used to confirm the geometrical features of these copper(II) complexes: the observation of negative redox potentials are in good agreement with the inferred geometry. All these results taken together suggest that peptide 1 provides a single metal binding site to which copper(II) binds strongly at neutral and basic pH and that the binding of the metal induces the formation of a stiffened structure in the HGGG peptide fragment.
Copper(II) binding modes in the prion octapeptide PHGGGWGQ: A spectroscopic and voltammetric study
Kállay C, Dávid A, Timári S, Nagy EM, Sanna D, Garribba E, Micera G, De Bona P, Pappalardo G, Rizzarelli E, Sóvágó I * Copper(II) complexes of rat amylin fragments(464 views) Dalton T (ISSN: 1477-9234, 1477-9226, 1477-9234electronic), 2011 Oct 14; 40(38): 9711-9721. Impact Factor:3.838 ViewExport to BibTeXExport to EndNote