Determination of the high resolution structure of the polypeptide chain in amyloid fibrils
Lead Research Organisation:
University of Cambridge
Department Name: Physics
Abstract
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Technical Summary
Amyloid fibrils are highly organised filamentous structures formed by the self-assembly of polypeptides, and in vivo they are implicated in a number of diseases including Alzheimer¿s Disease and type II diabetes. Despite the fact that many different chemically unrelated proteins form amyloid fibrils, the final fibrillar complexes appear to share similar fundamental structures. The primary objective of the proposed work is to determine the intermolecular organisation of polypeptide in a model amyloid fibril system at high resolution using solid-state NMR techniques. Our model system is an 11-amino acid peptide that readily self-assembles, and we have already had great success in determining the high resolution structure of the individual peptides in their fibrillar form. All that remains is to determine the three-dimensional organisation of the peptides in a fibrillar array. The experimental data will be combined with molecular dynamics simulations to confirm and predict intermolecular constraints, and using this combination of experimental and theoretical approaches we will build up the first high-resolution structure of a system that to date has remained intractable. The second objective of the proposal is to extend the knowledge and methodological experience gained from this model polypeptide system to a significantly larger protein of 84 amino acids, the SH3 domain of the p85a subunit of phosphatidyl-inositol-3 kinase. Such a protein is larger than any system measured by solid-state NMR techniques to date and thus represents a significant challenge. In the first instance, we propose to determine the complete sequence assignments for this protein, an essential first step towards the determination of a structure, and a goal achievable within the lifetime of the proposed project. All of these approaches will provide us with insight into a type of quaternary structure that has singular relevance to a wide range of degenerative diseases.
People |
ORCID iD |
Cait MacPhee (Principal Investigator) |
Publications
Bayro MJ
(2011)
Intermolecular structure determination of amyloid fibrils with magic-angle spinning and dynamic nuclear polarization NMR.
in Journal of the American Chemical Society
Nadaud PS
(2010)
Expression and purification of a recombinant amyloidogenic peptide from transthyretin for solid-state NMR spectroscopy.
in Protein expression and purification
Cole HL
(2010)
Characterizing early aggregates formed by an amyloidogenic peptide by mass spectrometry.
in Angewandte Chemie (International ed. in English)
Caporini MA
(2010)
Accurate determination of interstrand distances and alignment in amyloid fibrils by magic angle spinning NMR.
in The journal of physical chemistry. B
Description | We determined the high-resolution structure of a polypeptide in an amyloid fibril using a wide range of biophysical methods. It is the first time the atomic resolution structure of a native fibril has been achieved. |
Exploitation Route | Revealing the structure of a native fibril would allow the interrogation of potential binding sites that could inhibit self-assembly. Since amyloid fibres are linked to a wide range of human diseases, this is of potential relevance to the pharmaceutical industry. |
Sectors | Pharmaceuticals and Medical Biotechnology |
Description | Our published findings have been cited by those seeking small molecule inhibitors for protein aggregation diseases. Others have applied the methods we describe in a number of our publications to advance the use of solid-state NMR for the determination of protein structures. A further use of our research has been in the fields of biomaterials and nanotechnology. Protein fibres represent robust scaffolds with silk-like properties, with applications as cell scaffolds or slow-release formulations. A number of research groups worldwide have exploited our findings to extend our understanding of the mechanical properties of such materials. |
First Year Of Impact | 2009 |
Sector | Healthcare,Pharmaceuticals and Medical Biotechnology |