Dealing with Cu reduction in X-ray absorption spectroscopy experiments. Issue 8 (3rd July 2019)

• Record Type: Journal Article
• Authors: Stellato, Francesco; Chiaraluce, Roberta; Consalvi, Valerio; De Santis, Emiliano; La Penna, Giovanni; Proux, Olivier; Rossi, Giancarlo; Morante, Silvia
• Is Part Of: Metallomics. Volume 11:Issue 8(2019)
• Page Start: 1401
• Page End: 1410
• Publication Date: 2019-07-03
• Subjects: Metals -- Physiological effect -- Periodicals; 572.51
• DOI: 10.1039/c9mt00110g
• Languages: English
• ISSNs: 1756-5901

Abstract

Abstract : We prove in the exemplary case of the Cu(ii ) amyloid-β peptide complex that, at cryogenic temperatures, the time needed for collecting a good quality spectrum is significantly shorter than the time after which structural damage becomes appreciable. Abstract : In this paper we prove in the exemplary case of the amyloid-β peptide in complex with Cu(ii ) that at the current low temperatures employed in XAS experiments, the time needed for collecting a good quality XAS spectrum is significantly shorter than the time after which structural damage becomes appreciable. Our method takes advantage of the well-known circumstance that the transition of Cu from the oxidized to the reduced form under ionizing radiation can be quantified by monitoring a characteristic peak in the pre-edge region. We show that there exists a sufficiently large time window in which good XAS spectra can be acquired before the structure around the oxidized Cu(ii ) ion reorganizes itself into the reduced Cu(i ) "resting" structure. We suggest that similar considerations apply to other cases of biological interest, especially when dealing with macromolecules in complex with transition metal ions.