Title:Atomic Force Microscopy: The Characterisation of Amyloid Protein Structure in Pathology
Volume: 19
Issue: 32
Author(s): Maria J.E. Visser and Etheresia Pretorius*
Affiliation:
- Department of Physiological Sciences, Faculty of Science, Stellenbosch University, Stellenbosch, Private Bag X1 Matieland, 7602,South Africa
Keywords:
Atomic force microscopy, Protein structure, Amyloid, Disease, Correlative microscopy, NMR.
Abstract: Proteins are versatile macromolecules that perform a variety of functions and participate in
virtually all cellular processes. The functionality of a protein greatly depends on its structure and alterations
may result in the development of diseases. Most well-known of these are protein misfolding disorders,
which include Alzheimer’s and Parkinson’s diseases as well as type 2 diabetes mellitus, where
soluble proteins transition into insoluble amyloid fibrils. Atomic Force Microscopy (AFM) is capable of
providing a topographical map of the protein and/or its aggregates, as well as probing the nanomechanical
properties of a sample. Moreover, AFM requires relatively simple sample preparation, which presents
the possibility of combining this technique with other research modalities, such as confocal laser
scanning microscopy, Raman spectroscopy and stimulated emission depletion microscopy. In this review,
the basic principles of AFM are discussed, followed by a brief overview of how it has been applied
in biological research. Finally, we focus specifically on its use as a characterisation method to
study protein structure at the nanoscale in pathophysiological conditions, considering both molecules
implicated in disease pathogenesis and the plasma protein fibrinogen. In conclusion, AFM is a userfriendly
tool that supplies multi-parametric data, rendering it a most valuable technique.
