wizyta

od 2020-09-20

Title: Amyloid beta peptide aggregation process in the presence of sugar-based surfactants- conformational and structural studies

Source: Biophysical Journal

Year : 2018

Abstract:

The progression of Alzheimer's Disease (AD) is caused by aggregation process of amyloid β peptide (Aβ) [1]. The aggregation mechanism of Aβ peptides is still under discussion, because the process of Aβ oligomerization is relatively fast and it can be affected by many variables [2]. The control of Aβ aggregation is very hard to achieve, but use of selected specific surfactants may contribute to a better understanding of this process. The aim of this study was characterization of the structure and conformational changes in β-amyloid peptides induced by the presence of zwitterionic, sugar-based surfactants comprising a lactose moiety. Several different variants of β-amyloid peptides were selected for the study. The effect of surfactant concentration in solution was tested on Aβ1-42 peptide and its shorter variants. Selected solutions of tested β-amyloid peptides with surfactants were subjected to a series of solution scattering experiments using the synchrotron radiation (SR-SAXS). The SAXS data for these surfactants were collected on P12 beam line of EMBL (DESY). SR-SAXS studies exhibited the structure of various mixed (peptide-surfactant) assemblies. In our study we analyzed also the secondary structure of Aβ peptide in solutions with different concentrations of surfactant, using FTIR spectroscopy and circular dichroism (CD) methods. Atomic force microscopy (AFM) was used to characterize the morphology of Aβ assemblies. Particular attention was paid to analysis of small soluble oligomers that are currently believed to initiate development of brain disfunction in AD.

[1] J. Hardy and D. J. Selkoe, Science, 2002.
[2] J. A. Loureiro, S. Rocha, and M. do C. Pereira, J. Pept. Sci. Off. Publ. Eur. Pept. Soc., 2013.

Acknowledgments: The study was supported by research grant, Grant Diamentowy’’ from Ministry of Science and Higher Education (Poland) - DEC: 0011/DIA2015/44.

DOI: 10.1016/j.bpj.2017.11.1233   (Pobrane:  2020-07-21)