title: Amyloid-like fibrils in elastin-related polypeptides: structural characterization and elastic properties.
abstract: We report on the structural characterization of amyloid-like fibrils, self-assembled from synthetic polypentapeptides poly(ValGlyGlyLeuGly), whose monomeric sequence is a recurring, simple building block of elastin. This polymer adopts a beta-sheet structure as revealed by circular dichroism and Fourier transform infrared spectroscopy. Furthermore, Thioflavin-T and Congo red birefringence assays confirm the presence of amyloid-like structures. To analyze the supramolecular assembly and elastic properties of the fibrils, we employed atomic force microsocopy and spectroscopy, measuring also the elasticity of mature elastin for a comparative analysis. In the case of fibrils we estimated a Young's modulus ranging from 3.5 to 7 MPa, whereas for elastin it is around 1 MPa. The possibility to section individual fibrils with nanometric control by the AFM tip, realizing biomolecular gaps in the 100 nm range, is also demonstrated. These results are expected to open interesting perspectives for the fabrication of protein-inspired nanostructures with specific physical and chemical properties for applications in biotechnology and tissue engineering.
authors.affiliation: National Nanotechnology Laboratory of INFM-CNR, IIT Research Unit, ISUFI, University of Salento, Via per Arnesano, 73100 Lecce, Italy. loretta.delmercato@unile.it
authors.forename: Loretta L
authors.initials: LL
authors.lastname: del Mercato
authors.forename: Giuseppe
authors.initials: G
authors.lastname: Maruccio
authors.forename: Pier Paolo
authors.initials: PP
authors.lastname: Pompa
authors.forename: Brigida
authors.initials: B
authors.lastname: Bochicchio
authors.forename: Antonio M
authors.initials: AM
authors.lastname: Tamburro
authors.forename: Roberto
authors.initials: R
authors.lastname: Cingolani
authors.forename: Ross
authors.initials: R
authors.lastname: Rinaldi
mesh_terms: D000595:Amino Acid Sequence; D000682:Amyloid / Q000737:chemistry*; D052160:Benzothiazoles; D002942:Circular Dichroism; D003224:Congo Red / Q000032:analysis / Q000737:chemistry; D004549:Elastin / Q000737:chemistry*; D005456:Fluorescent Dyes / Q000737:chemistry; D006801:Humans; D018625:Microscopy, Atomic Force; D036103:Nanotechnology; D017433:Protein Structure, Secondary; D011506:Proteins / Q000737:chemistry*; D017550:Spectroscopy, Fourier Transform Infrared; D013314:Stress, Mechanical; D013844:Thiazoles / Q000032:analysis / Q000737:chemistry
chemical_list: D000682:Amyloid; D052160:Benzothiazoles; D005456:Fluorescent Dyes; D011506:Proteins; D013844:Thiazoles; C528055:poly(valyl-glycyl-glycyl-leucyl-glycyl); C009462:thioflavin T; D003224:Congo Red; D004549:Elastin