Correlation between nanomechanics and polymorphic conformations in amyloid fibrils

Area of Science:

• Biophysics
• Materials Science
• Nanotechnology

Background:

• Amyloid fibrils exhibit diverse morphologies, impacting their mechanical characteristics.
• Understanding structure-property relationships in amyloid nanomechanics is crucial.

Purpose of the Study:

• To develop a theoretical framework for calculating the mechanical properties of non-axisymmetric amyloid fibrils.
• To investigate how fibril polymorphism affects bending properties.

Main Methods:

• Applied formalisms from the theory of elasticity.
• Developed an original method for averaging the second area moment of inertia for non-axisymmetric fibrils.
• Derived theoretical expressions for bending properties of common polymorphic forms.

Main Results:

• Provided theoretical expressions for the bending properties of twisted ribbons, helical ribbons, and nanotubes.
• Benchmarked theoretical predictions against experimental data.
• Enabled accurate estimation of amyloid fibril elastic moduli.

Conclusions:

• The proposed method accurately estimates elastic moduli for amyloid fibrils.
• Offers insights into structure-property relationships in amyloid nanomechanics.
• Explains phenomena like helical ribbon closure into nanotubes.