Copper(II) directs formation of toxic amorphous aggregates resulting in inhibition of hen egg white lysozyme fibrillation under alkaline salt-mediated conditions

Sudeshna Ghosh, Nitin K. Pandey, Priyanka Banerjee, Koel Chaudhury, Nóra Veronika Nagy, Swagata Dasgupta

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15 Citations (Scopus)

Abstract

Hen egg white lysozyme (HEWL) adopts a molten globule-like state at high pH (~12.75) and is found to form amyloid fibrils at alkaline pH. Here, we report that Cu(II) inhibits self-association of HEWL at pH 12.75 both at 37 and 65 °C. A significant reduction in Thioflavin T fluorescence intensity, attenuation in β-sheet content and reduction in hydrophobic exposure were observed with increasing Cu(II) stoichiometry. Electron paramagnetic resonance spectroscopy suggests a 4N type of coordination pattern around Cu(II) during fibrillation. Cu(II) is also capable of altering the cytotoxicity of the proteinaceous aggregates. Fibrillar species of diverse morphology were found in the absence of Cu(II) with the generation of amorphous aggregates in the presence of Cu(II), which are more toxic compared to the fibrils alone.

Original languageEnglish
Pages (from-to)991-1007
Number of pages17
JournalJournal of Biomolecular Structure and Dynamics
Volume33
Issue number5
DOIs
Publication statusPublished - May 4 2015

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Keywords

  • Cu(II) stoichiometry
  • cytotoxicity
  • fibrillation
  • hen egg white lysozyme
  • inhibition
  • molten globule state

ASJC Scopus subject areas

  • Structural Biology
  • Molecular Biology

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