ǂThe ǂrole of buffers in wild-type HEWL amyloid fibril formation mechanism

Sandi Brudar (Author), Barbara Hribar (Author)

Abstract

Amyloid fibrils, highly ordered protein aggregates, play an important role in the onset of several neurological disorders. Many studies have assessed amyloid fibril formation under specific solution conditions, but they all lack an important phenomena in biological solutions—buffer specific effects. We have focused on the formation of hen egg-white lysozyme (HEWL) fibrils in aqueous solutions of different buffers in both acidic and basic pH range. By means of UV-Vis spectroscopy, fluorescence measurements and CD spectroscopy, we have managed to show that fibrillization of HEWL is affected by buffer identity (glycine, TRIS, phosphate, KCl-HCl, cacodylate, HEPES, acetate), solution pH, sample incubation (agitated vs. static) and added excipients (NaCl and PEG). HEWL only forms amyloid fibrils at pH = 2.0 under agitated conditions in glycine and KCl-HCl buffers of high enough ionic strength. Phosphate buffer on the other hand stabilizes the HEWL molecules. Similar stabilization effect was achieved by addition of PEG12000 molecules to the solution.

Keywords

lizocim;amiloidne fibrile;pufer-specifični efekti;lysozyme;amyloid fibrils;buffer-specific effects;

Data

Language:	English
Year of publishing:	2019
Typology:	1.01 - Original Scientific Article
Organization:	UL FKKT - Faculty of Chemistry and Chemical Technology
UDC:	577.322
COBISS:	1538128835
ISSN:	2218-273X
Views:	388
Downloads:	126
Average score:	0 (0 votes)
Metadata:

Other data

Secondary language:	Slovenian
Secondary keywords:	lizocim;amiloidne fibrile;pufer-specifični efekti;
Type (COBISS):	Article
Source comment:	Amyloid fibrils, highly ordered protein aggregates, play an important role in the onset of several neurological disorders. Many studies have assessed amyloid fibril formation under specific solution conditions, but they all lack an important phenomena in biological solutions—buffer specific effects. We have focused on the formation of hen egg-white lysozyme (HEWL) fibrils in aqueous solutions of different buffers in both acidic and basic pH range. By means of UV-Vis spectroscopy, fluorescence measurements and CD spectroscopy, we have managed to show that fibrillization of HEWL is affected by buffer identity (glycine, TRIS, phosphate, KCl-HCl, cacodylate, HEPES, acetate), solution pH, sample incubation (agitated vs. static) and added excipients (NaCl and PEG). HEWL only forms amyloid fibrils at pH = 2.0 under agitated conditions in glycine and KCl-HCl buffers of high enough ionic strength. Phosphate buffer on the other hand stabilizes the HEWL molecules. Similar stabilization effect was achieved by addition of PEG12000 molecules to the solution.
Pages:	str. 1-18
Volume:	ǂVol. ǂ9
Issue:	ǂiss. ǂ2
Chronology:	Feb. 2019
DOI:	10.3390/biom9020065
ID:	12642519