On the determination of the helical structure parameters of amyloid protofilaments by small-angle neutron scattering and atomic force microscopy

• Published in: Journal of applied crystallography Vol. 46; no. 1; pp. 224 - 233
• Main Authors: Avdeev, Mikhail V., Aksenov, Victor L., Gazová, Zuzana, Almásy, László, Petrenko, Viktor I., Gojzewski, Hubert, Feoktystov, Artem V., Siposova, Katarina, Antosova, Andrea, Timko, Milan, Kopcansky, Peter
• Format: Journal Article
• Language: English
• Published: 5 Abbey Square, Chester, Cheshire CH1 2HU, England International Union of Crystallography 01-02-2013; Blackwell Publishing Ltd
• Subjects: amyloid fibrils; atomic force microscopy; Crystallography; helical structures; hen egg white lysozyme; Materials science; Microscopy; Scattering; small-angle neutron scattering; Solvents
• ISSN: 1600-5767; 0021-8898; 1600-5767
• DOI: 10.1107/S0021889812050042

The helical structure of amyloid protofilaments of hen egg white lysozyme was analyzed by small‐angle neutron scattering (SANS) and atomic force microscopy (AFM). The structure of these formations in bulk solutions was adequately described by SANS in terms of a simplified model of a helix with spherical structural units. The found main helix parameters (pitch and effective diameter) are consistent with the results of AFM analysis for amyloid fibrils adsorbed on a mica surface. Both methods reveal a strong isotope effect on the structure of amyloid fibrils with respect to the substitution of heavy for light water in the solvent. Specific details responsible for the structural differences when comparing SANS and AFM data are discussed from the viewpoint of methodological aspects, the influence of different (native and adsorbed) amyloid states and sample preparation.