Journal: RSC Advances

Article Title: EPR spectroscopy reveals different Cu( ii ) coordination in APP 142–172 and APP 145–170 peptide fragments of amyloid precursor protein

doi: 10.1039/d6ra00647g

Figure Lengend Snippet: Experimental and simulated X-band CW-EPR spectra of the two copper–peptide complexes at pH 7.4. (A) Cu( ii )–APP 142–172 . (B) Cu( ii )–APP 145–170 . Black traces: Experimental spectra. Red traces: simulated spectra. In panel (B), the blue and green traces represent the individual simulated components (component I and component II), displayed at their fitted proportions as determined by EasySpin fitting (Table S1). Residual spectra are provided in Fig. S6.

Article Snippet: Low-temperature continuous-wave (CW) X-band EPR spectra were recorded on a Bruker X-band EMXplus 10/12 spectrometer equipped with an Oxford ESR-910 helium flow cryostat and ITC-503 temperature controller (Oxford Instruments Ltd, Oxfordshire, UK).

Techniques:

Journal: RSC Advances

Article Title: EPR spectroscopy reveals different Cu( ii ) coordination in APP 142–172 and APP 145–170 peptide fragments of amyloid precursor protein

doi: 10.1039/d6ra00647g

Figure Lengend Snippet: Fe( ii ) oxidation by Cu( ii )–peptide complexes under anaerobic conditions. (A and B) Spectra of Cu( ii )–APP 142–172 and Cu( ii )–APP 145–170 before (orange) and after (blue) addition of Fe( ii )–EDTA. (C and D) X-band CW-EPR spectra of Cu( ii )–APP 142–172 and Cu( ii )–APP 145–170 before (orange) and after (blue) addition of excess Fe( ii )–EDTA. After Fe( ii ) addition, a broad feature at g ≈ 4.3 (≈700 G) and a weak feature near g ′ ≈ 9.7 are observed, consistent with high-spin ( S = 5/2) Fe( iii ) in rhombic, strong-ZFS environments and indicative of substantial D -strain.

Article Snippet: Low-temperature continuous-wave (CW) X-band EPR spectra were recorded on a Bruker X-band EMXplus 10/12 spectrometer equipped with an Oxford ESR-910 helium flow cryostat and ITC-503 temperature controller (Oxford Instruments Ltd, Oxfordshire, UK).

Techniques: