Interaction studies of oxindole-derivatives with beta-amyloid peptides inhibiting its aggregation induced by metal ions

Author(s)

Wegermann, Camila Anchau ; Pirota, Valentina ; Monzani, Enrico ; Casella, Luigi ; Costa, Luiz Antonio Sodre ; Novato, Willian Tassio Gomes ; Machini, M. Teresa ; Ferreira, Ana Maria da Costa

• Document type: Journal article
• Source: Journal of Inorganic Biochemistry; v. 245, p. 16-pg., 2023-05-06.

Abstract

Some hydrazones and Schiff bases derived from isatin, an endogenous oxindole formed in the metabolism of tryptophan, were obtained to investigate their effects on in vitro aggregation of beta-amyloid peptides (A beta), mac-romolecules implicated in Alzheimer's disease. Some hydrazone ligands, prepared by condensation reactions of isatin with hydrazine derivatives, showed a large affinity binding to the synthetic peptides A beta, particularly to A beta 1-16. Measurements by NMR spectroscopy indicated that those interactions occur mainly at the metal binding site of the peptide, involving His6, His13, and His14 residues, and that hydrazone E-diastereoisomer interacts preferentially with the amyloid peptides. Experimental results were consistent with simulations using a docking approach, where it is demonstrated that the amino acid residues Glu3, His6, His13, and His14 are those that mostly interact with the ligands. Further, these oxindole-derived ligands can efficiently chelate copper(II) and zinc(II) ions, forming moderate stable [ML] 1:1 species. The corresponding formation constants were determined by UV/Vis spectroscopy, by titrations of the ligands with increasing amounts of metal salts, and the obtained log K values were in the range 2.74 to 5.11. Both properties, good affinity for amyloid peptides, and reasonably good capacity of chelating biometal ions, like copper and zinc, can explain the efficient inhibition of A beta fragments aggregation, as shown by experiments carried out with the oxindole derivatives in the presence of metal ions. (AU)

• FAPESP's process: 11/50318-1 - Development of compounds with pharmacological or medicinal interest and of systems for their transport, detection and recognition in biological media
• Grantee: Ana Maria da Costa Ferreira
• Support Opportunities: Research Projects - Thematic Grants
• FAPESP's process: 15/14360-4 - Magnetic bionanocatalysts: preparation, characterization, properties and use in protein and peptide chemistry
• Grantee: Maria Teresa Machini
• Support Opportunities: Regular Research Grants
• FAPESP's process: 13/07937-8 - Redoxome - Redox Processes in Biomedicine
• Grantee: Ohara Augusto
• Support Opportunities: Research Grants - Research, Innovation and Dissemination Centers - RIDC