title: Evidence of two oxidation states of copper during aggregation of hen egg white lysozyme (HEWL).
abstract: In vitro fibrillation of hen egg white lysozyme (HEWL) causes complete reduction of Cu(II) to Cu(I) at pH 7. Here in the present article, we have shown the presence of both Cu(II) and Cu(I) at pH 11 during fibrillation of HEWL using electron paramagnetic resonance and Raman spectroscopy. Our results suggest the existence of a partially reducing environment during fibrillation of hen egg white lysozyme at pH 11. The fibrillation process is governed by the pH of the solution and maximum fibrillation is found to occur at pH 11. Fibrils formed in the absence of Cu(II) were also found to cause significant hemolysis of RBC.
authors.affiliation: Department of Chemistry, Indian Institute of Technology, Kharagpur, Kharagpur 721302, India.
authors.forename: Sudeshna
authors.initials: S
authors.lastname: Ghosh
authors.affiliation: Department of Chemistry, Indian Institute of Technology, Kharagpur, Kharagpur 721302, India.
authors.forename: Nitin K
authors.initials: NK
authors.lastname: Pandey
authors.affiliation: Department of Physics, Indian Institute of Technology, Kharagpur, Kharagpur 721302, India.
authors.forename: Susmita
authors.initials: S
authors.lastname: Bhattacharya
authors.affiliation: Department of Physics, Indian Institute of Technology, Kharagpur, Kharagpur 721302, India.
authors.forename: Anushree
authors.initials: A
authors.lastname: Roy
authors.affiliation: Institute of Molecular Pharmacology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, 1025 Pusztaszeriút 59-67, Budapest, Hungary.
authors.forename: Nóra Veronika
authors.initials: NV
authors.lastname: Nagy
authors.affiliation: Department of Chemistry, Indian Institute of Technology, Kharagpur, Kharagpur 721302, India. Electronic address: swagata@chem.iitkgp.ernet.in.
authors.forename: Swagata
authors.initials: S
authors.lastname: Dasgupta
mesh_terms: D000682:Amyloid / Q000737:chemistry; D000818:Animals; D003300:Copper / Q000737:chemistry*; D004529:Egg White / Q000737:chemistry*; D005260:Female; D006863:Hydrogen-Ion Concentration; D007700:Kinetics; D008958:Models, Molecular; D009113:Muramidase / Q000737:chemistry*; D019906:Nuclear Magnetic Resonance, Biomolecular; D010084:Oxidation-Reduction; D066329:Protein Aggregates; D066263:Protein Aggregation, Pathological; D011487:Protein Conformation; D055503:Protein Multimerization; D013059:Spectrum Analysis, Raman
chemical_list: D000682:Amyloid; D066329:Protein Aggregates; D003300:Copper; C421864:hen egg lysozyme; D009113:Muramidase
keywords: Cu(II); Fibrillation; Hemolysis; Hen egg white lysozyme; Oxidation state