Probing the binding of Cu 2+ ions to a fragment of the Aβ (1–42) polypeptide using fluorescence spectroscopy, isothermal titration calorimetry and molecular dynamics simulations

Effect of Tetraphenylborate on Physicochemical Properties of Bovine Serum Albumin

“…It can be observed that the quenching (binding) constants decrease with the increase in the [B(Ph) 4 ] − concentration of the system, which can be assigned to the competition of SDS with [B(Ph) 4 ] − in BSA [28,29]. Furthermore, the estimated values of k q for all systems are of the order 10 12 M −1 •s −1 , which is approximately a few hundred times higher than the maximum value possible for the diffusion-controlled quenching-rate constant (2.0 × 10 10 M −1 •s −1 ) [30]. Since the values of bimolecular quenching rate constants are considered to be definitive in differentiating between dynamic and static quenching mechanisms, the predominant role of ground-state complexation (static quenching) in the investigated systems was confirmum albumin was measured using an extinction coefficient eqed.…”

“…) 4 ]:BSA molar ratios in the mixture, namely T m1 = 341.8 K and T m2 = 351.9 K for the saturation of the first binding sites (Na[B(Ph) 4 ]:BSA = 2.5:1) and T m1 = 349.2 K and T m2 = 356.2 K for BSA with both binding sites saturated (Na[B(Ph) 4 ]:BSA = 7:1).Molecules 2021, 26, 6565 8 of −1 s −1 )[30]. Since the values of bimolecular quenching rate constants are considered to be definitive in differentiating between dynamic and static quenching mechanisms, the predominant role of ground-state complexation (static quenching) in the investigated systems was confirmed.…”

Interactions of Aβ1-42 Peptide and Its Three Fragments (Aβ8-12, Aβ8-13, and Aβ5-16) with Selected Nonsteroidal Drugs and Compounds of Natural Origin

“…It should be noted that for HZ1 peptide the NMR-derived restrains were used for calculations. It has been previously confirmed, that the main conformation of HZ1 forms a well-defined bent structure in its central part (Ser4-His10) with quite flexible ends [32]. Figures 5-8 present the results of theoretical calculations obtained for both peptides with ibuprofen, aspirin, epinephrine, and anabasine, respectively.…”

“…The principal aim of this work was to study the binding properties of Aβ1-42 polypeptide to the chosen biologically active compounds. It should be noted that the conformation of the dominant family of HZ1 aligns appropriately on the corresponding section of the native Aβ1-42 [32], particularly when compared orientation of residues from the central part of the sequence with the most expanded side chains (i.e., tyrosine or histidine). Therefore, in particular, the attention has been focused on the influence of symmetrically oriented side chains of the amino acid residues in peptides under study on the stability of the resulting complexes.…”

A Pentapeptide with Tyrosine Moiety as Fluorescent Chemosensor for Selective Nanomolar-Level Detection of Copper(II) Ions

“…Studies of the complexes of amino acids and peptides with metal ions have been performed with a main goal to better understand transition metal complexes in proteins [21,22]. For instance, it has been shown that several ions, e.g., Cu 2+ and Zn 2+ , are involved in the amyloid-β peptide aggregation process, which presumably plays a main role in Alzheimer's disease [23]. From among all amino acids present in the amyloid-β (1-42) peptide sequence, histidine and tyrosine side chains are proven to have a distinct affinity for Cu 2+ and other metal cations [24].…”