2008-01-28
9:00 at HCI J 498

Nanoscale Characterization of Protein Aggregates and Nanofibers

Suzi Jarvis

University College, Dublin

Amyloid fibrils are quaternary protein structures formed from the non-specific folding and subsequent aggregation of proteins into supramolecular crossed b-sheet assemblies. Such structures are commonly regarded as ‘mistakes’ formed from ‘misfolded’ proteins due to their pathogenic association with neurodegenerative diseases such as Alzheimer’s and Parkinson’s. However, in recent years there has been increasing evidence to suggest that the amyloid structure is a generic form into which any polypeptide can fold, particularly in vitro under slightly denaturing conditions. We have recently discovered amyloid in various permanent and temporary natural adhesives. Using an atomic force microscope (AFM) we have been able to delicately pull apart amyloid fibrils in order to characterize their mechanical properties and thus provide an explanation for their mechanical strength based on ‘hidden length’ and ‘sacrificial bonds’ within the amyloid structure. We are now applying AFM to the mechanical and surface structural characterization of a range of pathogenic and physiological amyloid fibrils in order to identify the parameters that trigger the formation and influence subsequent structure and mechanical function, or indeed the pathogenic nature of the fibrils. In this way we hope to evaluate the feasibility of using amyloid fibrils as new biocompatible materials.