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Chapitre 4 : Structures de l’AS 71-82 en solution

4.2 Conclusions

Réussir à caractériser le peptide AS71-82 en solution revêt une grande importance avant de pouvoir s’intéresser aux structures que celui-ci adopte lors d’interactions avec des membranes modèles. Cette particularité de l’AS71-82, d’être soluble dans l’eau, permet d’affirmer que les changements structuraux observés en présence de membranes modèles, et détaillés dans les chapitres suivants, sont bien provoqués par ces interactions. La conformation désordonnée de l’AS71-82 en solution rappelle celle de sa protéine parent, AS35- 37. De plus, la plasticité structurelle de l’AS

71-82 est un argument supplémentaire en faveur du fait qu’il représente un bon modèle38.

groupes de recherche39-42, venant là encore renforcer l’idée qu’AS

71-82 constitue un bon modèle pour appréhender les comportements structuraux et dynamiques de l’AS.

4.3 Références

1. Bochicchio, B.; Tamburro Antonio, M., Polyproline II structure in proteins: Identification by chiroptical spectroscopies, stability, and functions. Chirality 2002, 14, 782-792.

2. Dukor, R. K.; Keiderling, T. A., Reassessment of the random coil conformation: vibrational CD study of proline oligopeptides and related polypeptides. Biopolymers 1991, 31, 1747- 1761.

3. Paterlini, M. G.; Freedman, T. B.; Nafie, L. A., Vibrational circular dichroism spectra of three conformationally distinct states and an unordered state of poly(L-lysine) in deuterated aqueous solution. Biopolymers 1986, 25, 1751-1765.

4. Smith, L. J.; Fiebig, K. M.; Schwalbe, H.; Dobson, C. M., The concept of a random coil: Residual structure in peptides and denatured proteins. Folding and Design 1996, 1, R95- R106.

5. Shi, Z.; Olson, C. A.; Rose, G. D.; Baldwin, R. L.; Kallenbach, N. R., Polyproline II structure in a sequence of seven alanine residues. Proc. Natl. Acad. Sci. U. S. A. 2002, 99, 9190. 6. Whittington, S. J.; Chellgren, B. W.; Hermann, V. M.; Creamer, T. P., Urea promotes

polyproline II helix formation:  Implications for protein denatured states. Biochemistry 2005, 44, 6269-6275.

7. Kentsis, A.; Mezei, M.; Gindin, T.; Osman, R., Unfolded state of polyalanine is a segmented polyproline II helix. Proteins 2004, 55, 493-501.

8. Kurouski, D.; Kar, K.; Wetzel, R.; Dukor, R. K.; Lednev, I. K.; Nafie, L. A., Levels of supramolecular chirality of polyglutamine aggregates revealed by vibrational circular dichroism. FEBS Lett. 2013, 587, 1638-1643.

9. Barth, A., Infrared spectroscopy of proteins. Biochim. Biophys. Acta, Bioenerg. 2007, 1767, 1073-1101.

10. Moradi, M.; Babin, V.; Roland, C.; Sagui, C., A classical molecular dynamics investigation of the free energy and structure of short polyproline conformers. J. Chem. Phys. 2010, 133, 125104.

11. Martial, B.; Lefèvre, T.; Buffeteau, T.; Auger, M., Vibrational circular dichroism reveals supramolecular chirality inversion of α-synuclein peptide assemblies upon interactions with anionic membranes. ACS Nano 2019, 13, 3232-3242.

12. Dehsorkhi, A.; Castelletto, V.; Hamley, I. W., Self-assembling amphiphilic peptides. J. Pept. Sci. 2014, 20, 453-467.

13. Shtilerman, M. D.; Ding, T. T.; Lansbury, P. T., Molecular crowding accelerates fibrillization of α-synuclein: Could an increase in the cytoplasmic protein concentration induce Parkinson's disease? Biochemistry 2002, 41, 3855-3860.

14. Aggeli, A.; Nyrkova, I. A.; Bell, M.; Harding, R.; Carrick, L.; McLeish, T. C. B.; Semenov, A. N.; Boden, N., Hierarchical self-assembly of chiral rod-like molecules as a model for peptide β-sheet tapes, ribbons, fibrils, and fibers. Proc. Natl. Acad. Sci. U. S. A. 2001, 98, 11857.

15. Baujard-Lamotte, L.; Noinville, S.; Goubard, F.; Marque, P.; Pauthe, E., Kinetics of conformational changes of fibronectin adsorbed onto model surfaces. Colloids Surf. B 2008, 63, 129-137.

16. Buell, A. K.; Dobson, C. M.; Knowles, T. P. J., The physical chemistry of the amyloid phenomenon: thermodynamics and kinetics of filamentous protein aggregation. Essays Biochem. 2014, 56, 11-39.

17. Ikenoue, T.; Lee, Y.-H.; Kardos, J.; Yagi, H.; Ikegami, T.; Naiki, H.; Goto, Y., Heat of supersaturation-limited amyloid burst directly monitored by isothermal titration calorimetry. Proc. Natl. Acad. Sci. U. S. A. 2014, 111, 6654-6659.

18. De Simone, A.; Esposito, L.; Pedone, C.; Vitagliano, L., Insights into stability and toxicity of amyloid-like oligomers by replica exchange molecular dynamics analyses. Biophys. J. 2008, 95, 1965-1973.

19. Berhanu, W. M.; Hansmann, U. H. E. In Advances in Protein Chemistry and Structural Biology; Karabencheva-Christova, T., Ed.; Academic Press: 2014; Vol. 96, pp 113-141. 20. Paslawski, W.; Andreasen, M.; Nielsen, S. B.; Lorenzen, N.; Thomsen, K.; Kaspersen, J. D.;

Pedersen, J. S.; Otzen, D. E., High stability and cooperative unfolding of α-synuclein oligomers. Biochemistry 2014, 53, 6252-6263.

21. Arora, A.; Ha, C.; Park, C. B., Insulin amyloid fibrillation at above 100°C: New insights into protein folding under extreme temperatures. Protein Sci. 2004, 13, 2429-2436.

22. Amunson, K. E.; Kubelka, J., On the temperature dependence of amide I frequencies of peptides in solution. J. Phys. Chem. B 2007, 111, 9993-9998.

23. Novo, M.; Freire, S.; Al-Soufi, W., Critical aggregation concentration for the formation of early Amyloid-β (1–42) oligomers. Sci. Rep. 2018, 8, 1783.

24. Clark, A. H.; Judge, F. J.; Richards, J. B.; Stubbs, J. M.; Suggett, A., Electron microscopy of network structures in thermally-induced globular protein gels. Int. J. Pept. Protein Res. 1981, 17, 380-392.

25. Casal, H. L.; Köhler, U.; Mantsch, H. H., Structural and conformational changes of β- lactoglobulin B: an infrared spectroscopic study of the effect of pH and temperature. Biochim. Biophys. Acta, Proteins Struc. Mol. Enzymol. 1988, 957, 11-20.

26. Adamcik, J.; Mezzenga, R., Adjustable twisting periodic pitch of amyloid fibrils. Soft Matter 2011, 7, 5437-5443.

27. Marek, P. J.; Patsalo, V.; Green, D. F.; Raleigh, D. P., Ionic strength effects on amyloid formation by amylin are a complicated interplay among Debye screening, ion selectivity, and Hofmeister effects. Biochemistry 2012, 51, 8478-8490.

28. Sikkink, L. A.; Ramirez-Alvarado, M., Salts enhance both protein stability and amyloid formation of an immunoglobulin light chain. Biophys. Chem. 2008, 135, 25-31.

29. Zurdo, J.; Guijarro, J. I.; Jiménez, J. L.; Saibil, H. R.; Dobson, C. M., Dependence on solution conditions of aggregation and amyloid formation by an SH3 domain. J. Mol. Biol. 2001, 311, 325-340.

30. Ullner, M.; Woodward, C. E.; Jönsson, B., A Debye–Hückel theory for electrostatic interactions in proteins. J. Chem. Phys. 1996, 105, 2056-2065.

31. Baldwin, R. L., How Hofmeister ion interactions affect protein stability. Biophys. J. 1996, 71, 2056-2063.

32. Collins, K. D., Ions from the Hofmeister series and osmolytes: effects on proteins in solution and in the crystallization process. Methods 2004, 34, 300-311.

33. Park, S.-B.; Yoon, J.-S.; Jang, S.-M.; Lee, K.-H.; Shin, S.-M., Computational study on oligomer formation of fibril-forming peptide of α-synuclein. Bull. Korean Chem. Soc. 2012, 33, 848-854.

34. Yoon, J.; Jang, S.; Lee, K.; Shin, S., Dimerization of fibril-forming segments of α-synuclein. Bull. Korean Chem. Soc 2009, 30, 1845-1850.

35. Fauvet, B.; Mbefo, M. K.; Fares, M.-B.; Desobry, C.; Michael, S.; Ardah, M. T.; Tsika, E.; Coune, P.; Prudent, M.; Lion, N., et al., α-Synuclein in central nervous system and from erythrocytes, mammalian cells, and Escherichia coli exists predominantly as disordered

36. Davidson, W. S.; Jonas, A.; Clayton, D. F.; George, J. M., Stabilization of α-synuclein secondary structure upon binding to synthetic membranes. J. Biol. Chem. 1998, 273, 9443- 9449.

37. Eliezer, D.; Kutluay, E.; Bussell Jr, R.; Browne, G., Conformational properties of α-synuclein in its free and lipid-associated states. J. Mol. Biol. 2001, 307, 1061-1073.

38. Deleersnijder, A.; Gerard, M.; Debyser, Z.; Baekelandt, V., The remarkable conformational plasticity of alpha-synuclein: blessing or curse? Trends Mol. Med. 2013, 19, 368-377. 39. Celej, María S.; Sarroukh, R.; Goormaghtigh, E.; Fidelio, Gerardo D.; Ruysschaert, J.-M.;

Raussens, V., Toxic prefibrillar α-synuclein amyloid oligomers adopt a distinctive antiparallel β-sheet structure. Biochem. J. 2012, 443, 719-726.

40. Klucken, J.; Outeiro, T. F.; Nguyen, P.; McLean, P. J.; Hyman, B. T., Detection of novel intracellular α-synuclein oligomeric species by fluorescence lifetime imaging. FASEB J. 2006, 20, 2050-2057.

41. Roberts, H. L.; Brown, D. R., Seeking a mechanism for the toxicity of oligomeric α- synuclein. Biomolecules 2015, 5, 282-305.

42. Gallea, J. I.; Celej, M. S., Structural insights into amyloid oligomers of the Parkinson disease- related protein α-synuclein. J. Biol. Chem. 2014, 289, 26733-26742.

Chapitre 5 : Vibrational Circular Dichroism Reveals