@article {2018|2129,
	title = {Probing the quality control mechanism of the  twin-arginine translocase with folding variants of a -designed heme protein.},
	journal = {J Biol Chem},
	volume = {293},
	year = {2018},
	month = {2018 05 04},
	pages = {6672-6681},
	abstract = {<p>Protein transport across the cytoplasmic membrane of bacterial cells is mediated by either the general secretion (Sec) system or the twin-arginine translocase (Tat). The Tat machinery exports folded and cofactor-containing proteins from the cytoplasm to the periplasm by using the transmembrane proton motive force as a source of energy. The Tat apparatus apparently senses the folded state of its protein substrates, a quality-control mechanism that prevents premature export of nascent unfolded or misfolded polypeptides, but its mechanistic basis has not yet been determined. Here, we investigated the innate ability of the model Tat system to recognize and translocate -designed protein substrates with experimentally determined differences in the extent of folding. Water-soluble, four-helix bundle maquette proteins were engineered to bind two, one, or no heme cofactors, resulting in a concomitant reduction in the extent of their folding, assessed with temperature-dependent CD spectroscopy and one-dimensional H NMR spectroscopy. Fusion of the archetypal N-terminal Tat signal peptide of the trimethylamine--oxide (TMAO) reductase (TorA) to the N terminus of the protein maquettes was sufficient for the Tat system to recognize them as substrates. The clear correlation between the level of Tat-dependent export and the degree of heme -induced folding of the maquette protein suggested that the membrane-bound Tat machinery can sense the extent of folding and conformational flexibility of its substrates. We propose that these artificial proteins are ideal substrates for future investigations of the Tat system\&$\#$39;s quality-control mechanism.</p>
},
	keywords = {Amino Acid Sequence, Bacterial Proteins, Circular Dichroism, Escherichia coli, Escherichia coli Proteins, Heme-Binding Proteins, Hemeproteins, Membrane Transport Proteins, Methylamines, Models, Molecular, Oxidoreductases, N-Demethylating, Periplasm, Protein Folding, Protein Sorting Signals, Protein Stability, Protein Transport, Proton Magnetic Resonance Spectroscopy, Substrate Specificity, Temperature},
	issn = {1083-351X},
	doi = {10.1074/jbc.RA117.000880},
	author = {Sutherland, George A and Grayson, Katie J and Adams, Nathan B P and Mermans, Daphne M J and Jones, Alexander S and Robertson, Angus J and Auman, Dirk B and Brindley, Amanda A and Sterpone, Fabio and Tuffery, Pierre and Philippe Derreumaux and Dutton, P Leslie and Robinson, Colin and Hitchcock, Andrew and Hunter, C Neil}
}
@article {2017|2036,
	title = {VLITL is a major cross-β-sheet signal for fibrinogen Aα-chain frameshift variants.},
	journal = {Blood},
	volume = {130},
	year = {2017},
	month = {2017 12 21},
	pages = {2799-2807},
	abstract = {<p>The first case of hereditary fibrinogen Aα-chain amyloidosis was recognized \&gt;20 years ago, but disease mechanisms still remain unknown. Here we report detailed clinical and proteomics studies of a French kindred with a novel amyloidogenic fibrinogen Aα-chain frameshift variant, Phe521Leufs, causing a severe familial form of renal amyloidosis. Next, we focused our investigations to elucidate the molecular basis that render this Aα-chain variant amyloidogenic. We show that a 49-mer peptide derived from the C-terminal part of the Phe521Leufs chain is deposited as fibrils in the patient\&$\#$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}
}
@article {2009|1830,
	title = {Replica exchange molecular dynamics simulations of coarse-grained proteins in implicit solvent.},
	journal = {J. Phys. Chem. B},
	volume = {113},
	number = {1},
	year = {2009},
	month = {jan},
	pages = {267{\textendash}274},
	keywords = {Amino Acid Sequence, Computer Simulation, Magnetic Resonance Spectroscopy, Molecular Sequence Data, Peptides, Protein Folding, Protein Structure, Proteins, Secondary, Solvents, Temperature, Thermodynamics},
	doi = {10.1021/jp805309e},
	author = {Y Chebaro and Xiao Dong and Rozita Laghaei and Philippe Derreumaux and Normand Mousseau}
}
@article {2009|2009,
	title = {Structural diversity of the soluble trimers of the human amylin(20-29) peptide revealed by molecular dynamics simulations},
	journal = {J. Chem. Phys.},
	volume = {130},
	number = {12},
	year = {2009},
	month = {mar},
	pages = {125101},
	keywords = {Amino Acid Sequence, Amyloid, Humans, Models, Molecular, Molecular Sequence Data, Peptide Fragments, Protein Multimerization, Protein Structure, Quaternary, Solubility, Solvents},
	doi = {10.1063/1.3097982},
	author = {Mo, Yuxiang and Lu, Yan and Wei, Guanghong and Philippe Derreumaux}
}
@article {2009|2019,
	title = {Thermodynamics and dynamics of amyloid peptide oligomerization are sequence dependent},
	journal = {Proteins: Struct., Funct., Bioinf.},
	volume = {75},
	number = {4},
	year = {2009},
	month = {jun},
	pages = {954{\textendash}963},
	keywords = {Amino Acid Sequence, Amyloid beta-Protein, beta 2-Microglobulin, Cluster Analysis, Computer Simulation, Models, Molecular, Peptide Fragments, Protein Multimerization, Protein Structure, Secondary, Structure-Activity Relationship, Thermodynamics},
	doi = {10.1002/prot.22305},
	author = {Lu, Yan and Philippe Derreumaux and Guo, Zhi and Mousseau, Normand and Wei, Guanghong}
}
