The synthesis and characterization of four new Ferrocene (Fc) bioconjugates, bearing a podant (Lys)-Leu-Val-Phe-Phe motif, namely the hydrophobic sequence of amyloid-β-peptides (Aβ), is reported. The Fc-peptide conjugates are characterized by a reversible redox activity and the ability to undergo hydrophobic and hydrogen bonding interactions. Biomolecular interactions between Fc-bioconjugates with Aβ12–28 fragments were studied by circular dichroism (CD), transmission electron microscopy (TEM), and electrochemistry. All four Fc-peptides interacted favourable with Aβ12–28 and prevented fibril formation, the extent of which depended on the length of the peptide and the nature of the C-terminal group. The aggregates obtained for the Aβ12–28/Fc-peptide mixtures range from short fibrils to spherical aggregates. We demonstrated that in solution the peptide sequence and peptide charge affect the biomolecular interactions. Fc-peptide interactions with immobilized Aβ12–28-Cys films on Au surfaces were detected by measuring the current response of the Fc redox process. The formal redox potential, E0, at ∼440 (10) mV and ipc/ipa at 0.9 were observed characteristic for the monosubstituted Fc-derivative undergoing a one-electron redox process. On the surface, methyl ester-protected Fc-peptides (1 and 3) interacted only weakly with Aβ12–28-Cys films, giving rise to minimal redox activity. In contrast, charged Fc-peptides (2 and 4) gave a significant electrochemical readout following the interaction with Aβ12−28-Cys films. Interestingly, the Fc-peptide charge dictates the surface-assisted interactions, while hydrophobic and ionic effects contribute to the overall solution behaviour of the Fc-bioconjugates with Aβ12–28.
If you can't find a tool you're looking for, please click the link at the top of the page to "Go to old article view". Alternatively, view our Knowledge Base articles for additional help. Your feedback is important to us, so please let us know if you have comments or ideas for improvement.