Investigating the inhibitory effects of zinc ions on amyloid fibril formation of hen egg-white lysozyme.
The amyloid fibrils derived from protein and peptide self-assembly have been studied in many diseases. In the present study, in combination with Thioflavin T(ThT) assay, Congo red(CR),transmission electron microscopy and cell cytotoxicity assay, we investigated the influence of zinc ions on amyloid fibril formation using hen egg white lysozyme (HEWL) as a model protein under high temperature and acidic pH conditions. We observed that HEWL tended to form the amyloid fibrils at pH 2.0 and 60°C, which was consistent with the previous studies. However, as the concentrations of zinc ions increased, the amounts of amyloid fibrils of HWEL gradually reduced, but the overall morphology of individual amyloid fibril was not significantly altered whether or not zinc ions were present. Moreover, by using circular dichroism (CD), ANS and intrinsic fluorescence spectra, we illustrated that zinc ions inhibited the formation of β-sheet and exposure of hydrophobic regions of HEWL. This work would help to understand the molecular mechanism of amyloid fibril formation.
Department of Physics, Science of College, Nanjing Agricultural University, Nanjing 210095, PR China. Electronic address: mabaoliang@njau.edu.cn.
Baoliang
B
Ma
Department of Physics, Science of College, Nanjing Agricultural University, Nanjing 210095, PR China.
Fan
F
Zhang
Department of Physics, Science of College, Nanjing Agricultural University, Nanjing 210095, PR China.
Xiaofei
X
Wang
Department of Physics, Science of College, Nanjing Agricultural University, Nanjing 210095, PR China.
Xudong
X
Zhu
D000682:Amyloid / Q000737:chemistry / Q000187:drug effects*; D000818:Animals; D002645:Chickens; D002942:Circular Dichroism; D057927:Hydrophobic and Hydrophilic Interactions; D007477:Ions / Q000737:chemistry; D007700:Kinetics; D046529:Microscopy, Electron, Transmission; D009113:Muramidase / Q000737:chemistry / Q000187:drug effects*; D013696:Temperature; D015032:Zinc / Q000737:chemistry*
D000682:Amyloid; D007477:Ions; C421864:hen egg lysozyme; D009113:Muramidase; D015032:Zinc
Amyloid fibrils; Hen egg white lysozyme (HEWL); Metal ions