Synthetic β-sheets mimicking fibrillar and oligomeric structures for evaluation of spectral X-ray scattering technique for biomarker quantification

Table 1 Summary of reported secondary structures and features of nanoscale structures of various pathogenic proteins in neurodegenerative diseases

Protein	β-Amyloid plaque	α- synuclein Lewy body	Tau tangle	Prion	TDP-43
Disease referring	AD	PD	Down’s syndrome	CJD, TSE	FTLD-TDP
Major secondary structure	β-sheet	β-sheet	β-sheet	β-sheet [38]	β-sheet
β-sheet IR absorption wavenumber (cm⁻¹)	1632 [39], 1628 [40]	1628, 1680 [41]	1628 [42, 43]	1630, 1628, 1618, 1614 [44]	1626 [45]
% β-sheet	53 [40, 46, 47]	LB core: 49 LB halo: 64 [41]	57 [48]	36–42, 54^a [49, 50]	52 [51] Wild type: 40 [45]
Conformation, X-ray peak positions (nm)	cross-β, 0.476, 1.06 [52]	cross-β, 0.47, 1 [12, 53]	cross-β, 0.47, 1.3 [48]	cross-β [54], 0.48,1.05^a [55]	cross-β^b, 0.48, 1.0^c [56, 57]
Reported filament diameters (nm)	10–20 [58,59,60]	5–20 [61,62,63]	8–20 [23]	9–20 [64,65,66,67]	15–25 [57, 68, 69]

^aFor scrapie PrP [49], ^bSome studies have also reported that not all TDP-43 aggregates have cross β-sheet structures [70], ^cIn-vitro fibrillization, FTLD-TDP: frontotemporal lobar degeneration with TPD-43-immunoreactive pathology, CJD: Creutzfeldt-Jakob disease, TSE: transmissible spongiform encephalopathies

ISSN: 2045-3701