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Monitoring early-stage β-amyloid dimer aggregation by histidine site-specific two-dimensional infrared spectroscopy in a simulation study.
- Source :
- Physical Chemistry Chemical Physics (PCCP); 8/21/2022, Vol. 24 Issue 31, p18691-18702, 12p
- Publication Year :
- 2022
-
Abstract
- Monitoring early-stage β-amyloid (Aβ) dimerization is a formidable challenge for understanding neurological diseases. We compared β-sheet formation and histidine site-specific two-dimensional infrared (2D IR) spectroscopic signatures of Aβ dimers with different histidine states (δ; N<superscript>δ1</superscript>–H, ε; N<superscript>ε2</superscript>–H, or π; both protonated). Molecular dynamics (MD) simulations revealed that β-sheet formation is favored for the δδδ:δδδ and πππ:πππ tautomeric isomers showing strong couplings and frequent contacts between the central hydrophobic core and C-terminus compared with the εεε:εεε isomer. Characteristic blue-shifts in the 2D IR central bands were observed upon monomer-dimer transformation. The εεε:εεε dimer exhibited larger frequency shifts than δδδ:δδδ and πππ:πππ implying that the red-shift may have a correlation with N<superscript>δ1</superscript>–H(δ) protonation. Our results support the tautomerization/protonation hypothesis that attributes Aβ misfolding to histidine tautomers as a possible primary initiator for Aβ aggregation and facilitates the application of histidine site-specific 2D IR spectroscopy for studying early-stage Aβ self-assembly. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 14639076
- Volume :
- 24
- Issue :
- 31
- Database :
- Complementary Index
- Journal :
- Physical Chemistry Chemical Physics (PCCP)
- Publication Type :
- Academic Journal
- Accession number :
- 158477413
- Full Text :
- https://doi.org/10.1039/d2cp02479a