I am pleased and honoured to welcome you in Genoa for EBSA2009, the 7 th European Biophysics Cong... more I am pleased and honoured to welcome you in Genoa for EBSA2009, the 7 th European Biophysics Congress. While celebrating the EBSA 25 years Anniversary it does not escape from our notice the interest in, and expanded development of Biophysics in Europe. As well, the international recognition of the EBSA Congress is growing along with the popularity of the EBSA scientific voice, namely the European Biophysics Journal superbly managed by Anthony Watts, published by Springer and which is so crucial to the survival and existence ...
The interest in elucidating the role of metals in amyloid diseases (to the group of which the Alz... more The interest in elucidating the role of metals in amyloid diseases (to the group of which the Alzheimer’s disease – AD – belongs) has significantly increased after noticing that Cu and Zn chelators can be used to solubilize the amyloid-beta aggregates (Abeta-aggregates) [1, 2], which appear to make up the fibrillar material associated with AD. There exist in the literature conflicting statements about the role of Cu2+ and Zn2+ ions in providing protection against or acting as promoters of plaques formation. Recent X-ray Absorption Spectroscopy experiments designed to study the metal coordination mode in Cu-Abeta and Zn-Abeta complexes [3, 4] have been able to detect visible differences between Zn and Cu samples that are suggestive of dissimilar structural roles of the two ions. Somewhat contradictory results concern moreover the Cu coordination mode. On the one hand, in fact, NMR data on copper complexed with Abeta(1-28) [5] and Abeta(1-40) [6] peptides suggest that three Histidines...
A proposal for building a new Free Electron Laser facility at the Laboratori Nazionali di Frascat... more A proposal for building a new Free Electron Laser facility at the Laboratori Nazionali di Frascati, EuPRAXIA@SPARC_LAB, is at present under consideration. This FEL facility will exploit plasma acceleration to produce ultra-bright photon pulses with durations of few femtoseconds down to the wavelengths between 2 and 4 nm, in the so called “water window”. The main class of experiments to be performed will include coherent diffraction imaging, soft X-ray absorption spectroscopy, Raman and photofragmentation measurements. In this article we present the updates on the photon beamlines design for the facility.
The redox activity of Cu ions bound to the amyloid‐β (Aβ) peptide is implicated as a source of ox... more The redox activity of Cu ions bound to the amyloid‐β (Aβ) peptide is implicated as a source of oxidative stress in the context of Alzheimer's disease. In order to explain the efficient redox cycling between CuII‐Aβ (distorted square‐pyramidal) and CuI‐Aβ (digonal) resting states, the existence of a low‐populated “in‐between” state, prone to bind Cu in both oxidation states, has been postulated. Here, we exploited the partial X‐ray induced photoreduction at 10 K, followed by a thermal relaxation at 200 K, to trap and characterize by X‐ray Absorption Spectroscopy (XAS) a partially reduced Cu‐Aβ1–16 species different from the resting states. Remarkably, the XAS spectrum is well‐fitted by a previously proposed model of the “in‐between” state, hence providing the first direct spectroscopic characterization of an intermediate state. The present approach could be used to explore and identify the catalytic intermediates of other relevant metal complexes.
The development of the synchrotron radiation sources allows now to extend x-ray absorption spectr... more The development of the synchrotron radiation sources allows now to extend x-ray absorption spectroscopy to aqueous solutions of biological molecules. Preliminary unpublished results by Yuen et al.[1] reported an energy shift of the K edge of about 5 eV going from the deoxy to ligated derivatives of hemoglobin. Stimulated by this finding we have undertaken a more extensive study of the K-edge absorption spectra for several derivatives of human HbA.
I am pleased and honoured to welcome you in Genoa for EBSA2009, the 7 th European Biophysics Cong... more I am pleased and honoured to welcome you in Genoa for EBSA2009, the 7 th European Biophysics Congress. While celebrating the EBSA 25 years Anniversary it does not escape from our notice the interest in, and expanded development of Biophysics in Europe. As well, the international recognition of the EBSA Congress is growing along with the popularity of the EBSA scientific voice, namely the European Biophysics Journal superbly managed by Anthony Watts, published by Springer and which is so crucial to the survival and existence ...
The interest in elucidating the role of metals in amyloid diseases (to the group of which the Alz... more The interest in elucidating the role of metals in amyloid diseases (to the group of which the Alzheimer’s disease – AD – belongs) has significantly increased after noticing that Cu and Zn chelators can be used to solubilize the amyloid-beta aggregates (Abeta-aggregates) [1, 2], which appear to make up the fibrillar material associated with AD. There exist in the literature conflicting statements about the role of Cu2+ and Zn2+ ions in providing protection against or acting as promoters of plaques formation. Recent X-ray Absorption Spectroscopy experiments designed to study the metal coordination mode in Cu-Abeta and Zn-Abeta complexes [3, 4] have been able to detect visible differences between Zn and Cu samples that are suggestive of dissimilar structural roles of the two ions. Somewhat contradictory results concern moreover the Cu coordination mode. On the one hand, in fact, NMR data on copper complexed with Abeta(1-28) [5] and Abeta(1-40) [6] peptides suggest that three Histidines...
A proposal for building a new Free Electron Laser facility at the Laboratori Nazionali di Frascat... more A proposal for building a new Free Electron Laser facility at the Laboratori Nazionali di Frascati, EuPRAXIA@SPARC_LAB, is at present under consideration. This FEL facility will exploit plasma acceleration to produce ultra-bright photon pulses with durations of few femtoseconds down to the wavelengths between 2 and 4 nm, in the so called “water window”. The main class of experiments to be performed will include coherent diffraction imaging, soft X-ray absorption spectroscopy, Raman and photofragmentation measurements. In this article we present the updates on the photon beamlines design for the facility.
The redox activity of Cu ions bound to the amyloid‐β (Aβ) peptide is implicated as a source of ox... more The redox activity of Cu ions bound to the amyloid‐β (Aβ) peptide is implicated as a source of oxidative stress in the context of Alzheimer's disease. In order to explain the efficient redox cycling between CuII‐Aβ (distorted square‐pyramidal) and CuI‐Aβ (digonal) resting states, the existence of a low‐populated “in‐between” state, prone to bind Cu in both oxidation states, has been postulated. Here, we exploited the partial X‐ray induced photoreduction at 10 K, followed by a thermal relaxation at 200 K, to trap and characterize by X‐ray Absorption Spectroscopy (XAS) a partially reduced Cu‐Aβ1–16 species different from the resting states. Remarkably, the XAS spectrum is well‐fitted by a previously proposed model of the “in‐between” state, hence providing the first direct spectroscopic characterization of an intermediate state. The present approach could be used to explore and identify the catalytic intermediates of other relevant metal complexes.
The development of the synchrotron radiation sources allows now to extend x-ray absorption spectr... more The development of the synchrotron radiation sources allows now to extend x-ray absorption spectroscopy to aqueous solutions of biological molecules. Preliminary unpublished results by Yuen et al.[1] reported an energy shift of the K edge of about 5 eV going from the deoxy to ligated derivatives of hemoglobin. Stimulated by this finding we have undertaken a more extensive study of the K-edge absorption spectra for several derivatives of human HbA.
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Papers by Silvia Morante