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Origin of enhanced VCD in amyloid fibril spectra: Effect of deuteriation and pH
Author(s) -
Pazderková Markéta,
Pazderka Tomáš,
Shanmugasundaram Maruda,
Dukor Rina K.,
Lednev Igor K.,
Nafie Laurence A.
Publication year - 2017
Publication title -
chirality
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.43
H-Index - 77
eISSN - 1520-636X
pISSN - 0899-0042
DOI - 10.1002/chir.22722
Subject(s) - chemistry , supramolecular chirality , fibril , chirality (physics) , vibrational circular dichroism , supramolecular chemistry , circular dichroism , crystallography , crystal structure , biochemistry , nambu–jona lasinio model , chiral symmetry breaking , physics , quantum mechanics , quark
Supramolecular chirality of amyloid fibrils, protein aggregates related to many neurodegenerative diseases, is a remarkable property associated with fibril structure and polymorphism. Since its discovery almost 10 years ago there is still little understanding of this phenomenon, including the cause of the highly enhanced vibrational circular dichroism (VCD) intensity arising from fibril supramolecular chirality. In this study, VCD spectra, enhanced by filament supramolecular chirality, are presented for lysozyme and insulin fibrils above and below pH 2 and after deuterium exchange, above and below pD 2. Supramolecular chirality (observed by VCD) and fibril morphology (documented by atomic force microscopy) are not affected by protein deuteriation. In D 2 O the fibril VCD sign pattern changes to fewer bands, with implications for the amide I/II origin of enhanced VCD intensity. Separation of amide I and II signals will facilitate calculations of enhanced VCD spectra of amyloid fibrils and enable a better understanding of the origin of the VCD sign pattern.