@article {2020|2075,
	title = {Characterization of β-turns by electronic circular dichroism spectroscopy: a coupled molecular dynamics and time-dependent density functional theory computational study.},
	journal = {Phys Chem Chem Phys},
	volume = {22},
	year = {2020},
	month = {2020 Jan 21},
	pages = {1611-1623},
	abstract = {<p>Electronic circular dichroism is one of the most used spectroscopic techniques for peptide and protein structural characterization. However, while valuable experimental spectra exist for α-helix, β-sheet and random coil secondary structures, previous studies showed important discrepancies for β-turns, limiting their use as a reference for structural studies. In this paper, we simulated circular dichroism spectra for the best-characterized β-turns in peptides, namely types I, II, I\&$\#$39; and II\&$\#$39;. In particular, by combining classical molecular dynamics simulations and state-of-the-art quantum time-dependent density functional theory (with the polarizable embedding multiscale model) computations, two common electronic circular dichroism patterns were found for couples of β-turn types (namely, type I/type II\&$\#$39; and type II/type I\&$\#$39;), at first for a minimal di-peptide model (Ace-Ala-Ala-NHMe), but also for all sequences tested with non-aromatic residues in the central positions. On the other hand, as expected, aromatic substitution causes important perturbations to the previously found ECD patterns. Finally, by applying suitable approximations, these patterns were subsequently rationalized based on the exciton chirality rule. All these results provide useful predictions and pave the way for a possible experimental characterization of β-turns based on circular dichroism spectroscopy.</p>
},
	keywords = {Circular Dichroism, Computational Chemistry, Computer Simulation, Molecular Dynamics Simulation, Protein Conformation, beta-Strand, Protein Structure, Tertiary},
	issn = {1463-9084},
	doi = {10.1039/c9cp05776e},
	author = {Migliore, Mattia and Bonvicini, Andrea and Tognetti, Vincent and Guilhaudis, Laure and Marc Baaden and Oulyadi, Hassan and Joubert, Laurent and S{\'e}galas-Milazzo, Isabelle}
}
@article {2017|2036,
	title = {VLITL is a major cross-β-sheet signal for fibrinogen Aα-chain frameshift variants.},
	journal = {Blood},
	volume = {130},
	year = {2017},
	month = {2017 12 21},
	pages = {2799-2807},
	abstract = {<p>The first case of hereditary fibrinogen Aα-chain amyloidosis was recognized \&gt;20 years ago, but disease mechanisms still remain unknown. Here we report detailed clinical and proteomics studies of a French kindred with a novel amyloidogenic fibrinogen Aα-chain frameshift variant, Phe521Leufs, causing a severe familial form of renal amyloidosis. Next, we focused our investigations to elucidate the molecular basis that render this Aα-chain variant amyloidogenic. We show that a 49-mer peptide derived from the C-terminal part of the Phe521Leufs chain is deposited as fibrils in the patient\&$\#$39;s kidneys, establishing that only a small portion of Phe521Leufs directly contributes to amyloid formation in vivo. In silico analysis indicated that this 49-mer Aα-chain peptide contained a motif (VLITL), with a high intrinsic propensity for β-aggregation at residues 44 to 48 of human renal fibrils. To experimentally verify the amyloid propensity of VLITL, we generated synthetic Phe521Leufs-derived peptides and compared their capacity for fibril formation in vitro with that of their VLITL-deleted counterparts. We show that VLITL forms typical amyloid fibrils in vitro and is a major signal for cross-β-sheet self-association of the 49-mer Phe521Leufs peptide identified in vivo, whereas its absence abrogates fibril formation. This study provides compelling evidence that VLITL confers amyloidogenic properties to Aα-chain frameshift variants, yielding a previously unknown molecular basis for the pathogenesis of Aα-chain amyloidosis.</p>
},
	keywords = {Amino Acid Motifs, Amino Acid Sequence, Amyloid, Amyloidosis, Familial, Fibrinogen, Frameshift Mutation, Humans, Kidney, Protein Conformation, beta-Strand},
	issn = {1528-0020},
	doi = {10.1182/blood-2017-07-796185},
	author = {Garnier, Cyrille and Briki, Fatma and Nedelec, Brigitte and Le Pogamp, Patrick and Dogan, Ahmet and Rioux-Leclercq, Nathalie and Goude, Renan and Beugnet, Caroline and Martin, Laurent and Delpech, Marc and Bridoux, Frank and Grateau, Gilles and Doucet, Jean and Philippe Derreumaux and Valleix, Sophie}
}
