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Initial Steps of Amyloidogenic Peptide Assembly Revealed by Cold‐Ion Spectroscopy
Author(s) -
Ujma Jakub,
Kopysov Vladimir,
Nagornova Natalia S.,
Migas Lukasz G.,
Lizio Maria Giovanna,
Blanch Ewan W.,
MacPhee Cait,
Boyarkin Oleg V.,
Barran Perdita E.
Publication year - 2018
Publication title -
angewandte chemie international edition
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.831
H-Index - 550
eISSN - 1521-3773
pISSN - 1433-7851
DOI - 10.1002/anie.201710188
Subject(s) - pentamer , trimer , tetramer , monomer , oligomer , chemistry , peptide , structural motif , crystallography , infrared spectroscopy , residue (chemistry) , fibril , spectroscopy , protein secondary structure , photochemistry , stereochemistry , dimer , organic chemistry , biochemistry , polymer , physics , quantum mechanics , enzyme
The early stages of fibril formation are difficult to capture in solution. We use cold‐ion spectroscopy to examine an 11‐residue peptide derived from the protein transthyretin and clusters of this fibre‐forming peptide containing up to five units in the gas phase. For each oligomer, the UV spectra exhibit distinct changes in the electronic environment of aromatic residues in this peptide compared to that of the monomer and in the bulk solution. The UV spectra of the tetra‐ and pentamer are superimposable but differ significantly from the spectra of the monomer and trimer. Such a spectral evolution suggests that a common structural motif is formed as early as the tetramer. The presence of this stable motif is further supported by the low conformational heterogeneity of the tetra‐ and pentamer, revealed from their IR spectra. From comparison of the IR‐spectra in the gas and condensed phases, we propose putative assignments for the dominant motif in the oligomers.