The Characterization of Multifaceted PREP1 Peptides Provides Insights into Correlations between Spectroscopic and Structural Properties of Amyloid-like Assemblies

Chemistry. 2024 Apr 29:e202400846. doi: 10.1002/chem.202400846. Online ahead of print.ABSTRACTThe widespread ability of proteins and peptides to self-assemble by forming cross-β structure is one of the most significant discoveries in structural biology. Intriguingly, the cross-β association of proteins/peptides may generate intricate supramolecular architectures with uncommon spectroscopic properties. We have recently characterized self-assembled peptides extracted from the PREP1 protein that are endowed with interesting structural/spectroscopic properties. We here demonstrate that the green fluorescence emission of the peptide PREP1[117-132] (λem ~ 520 nm), can be induced by excitation with UV radiation. The associated unusually large Stokes shift (Δλ ~ 150 nm) represents, to the best of our knowledge, the first evidence of an internal resonance energy transfer in amyloid-like structures, where the blue emission of some assemblies becomes the excitation radiation for others. Moreover, the characterization of PREP1[117-132] variants provides insights into the sequence/structure and structure/spectroscopic properties relationships. Our data suggests that the green fluorescence is plausibly associated with antiparallel β-sheet states of the peptide whereas parallel β-sheet assemblies are only endowed with blue fluorescence. Notably, the different PREP1[117-132] variants also form assemblies characterized by distinct morphologies. Indeed, the parent peptide and single mut...

Source: Chemistry - April 29, 2024 Category: Chemistry Authors: Alessandra Monti Pasqualina Liana Scognamiglio Menotti Ruvo Luigi Vitagliano Nunzianna Doti Source Type: research