Characterization by atomic force microscopy and cryoelectron microscopy of tau polymers assembled in Alzheimer's disease¹

Article type: Research Article

Authors: Moreno-Herrero, Fernando^a | Valpuesta, José M.^c | Pérez, Mar^b | Colchero, Jaime^a | Baró, Arturo M.^a | Avila, Jesús^{b; *} | Garcini, Esteban Montejo de^b

Affiliations: [a] Departamento de Física de la Materia Condensada, Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain | [b] Centro de Biología Molecular “Severo Ochoa” (UAM-CSIC), Facultad de Ciencias, Universidad Autónoma de Madrid, 28049 Madrid, Spain | [c] Centro Nacional de Biotecnología (CSIC), Campus de la Universidad Autónoma de Madrid, 28049 Madrid, Spain

Correspondence: [*] Corresponding author: Jesús Avila, Centro de Biología Molecular "Severo Ochoa", Fac. Ciencias, Universidad Autönoma de Madrid, Cantoblanco, 28049 Madrid, Spain. Tel.: +34 91 3978440; Fax: +34 91 3974799; E-mail: [email protected].

Note: [1] This work was supported by a grant of Comunidad Autónoma de Madrid (to A.M.B.) and by grants from CICYT (Spain) and Fundación La Caixa.

Abstract: The structure of the Paired Helical filaments (PHF), a polymer of the microtubule associated protein tau, has been studied by Atomic Force Microscopy (AFM) and by cryoelectron microscopy. Mica and graphite were used as substrates in the AFM analysis with no differences in the results. A banding pattern of 8–12 nm width within the helical structure is found when detailed analysis of the data is performed. High AFM resolution images obtained by using an ultra sharp tip confirm the previous results and suggest that the structures observed are compatible with a helical ribbon made up of two parallel strands. These results were confirmed by cryoelectron microscopy experiments.

Keywords: tau protein, assembly, neurodegeneration, Alzheimer's disease, Atomic Force Microscopy, Cryoelectron microscopy

DOI: 10.3233/JAD-2001-3502

Journal: Journal of Alzheimer's Disease, vol. 3, no. 5, pp. 443-451, 2001