Effects of oxidation on redox and cytotoxic properties of copper complex of Aβ1–16 peptide

Abstract

The effect of oxidation on redox and cytotoxic properties of copper complex of amyloid beta (Aβ) peptide was studied by gamma radiolysis. The oxidation of Aβ1–16 and Aβ1–16/Cu(II) complex was carried out using hydroxyl (^•OH) radicals produced by gamma radiolysis and the products were analyzed using mass spectrometry. The presence of Cu(II) was found to enhance the oxidation of Aβ1–16 peptide. The oxidation of residues Asp1, His6, and His13 was enhanced due to their involvement in copper binding. The oxidation of His residues of Aβ1–16 peptide, which are chiefly responsible for copper binding, resulted in altered redox properties and subsequently in higher cytotoxicity of the Aβ1–16 peptide in SH-SY5Y cells.

Keywords::

• free radicals
• amyloid β
• gamma radiolysis
• copper
• mass spectrometry

Acknowledgments

Authors thank Mrs. A. A. Athawale, Department of Chemistry, University of Pune for gamma radiolysis facility; Ms. Snigdha Dhali, Proteomics Laboratory, NCCS for the help in mass spectral measurements; and Dr. K. M. Paknikar, Centre for Nanobiosiences, Agharkar Research Institute for cyclic voltammetry facility.

Declaration of interest

The authors report no declarations of interest. The authors alone are responsible for the content and writing of the paper.

This work was supported by the funds from Department of Biotechnology, India (BT/PR3871/MED/30/830/2012). SNR thanks UGC, Government of India for SRF.