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PhD STUDENTSHIPS Biomedical Sciences Research Complex |
Single-molecule TIRF and FCS spectroscopy of protein-lipid interactions related to Alzheimer’s disease
The ability of proteins, nucleic acids and lipid molecules to assembly in a variety of structures underpins of life processes. However, under cellular stress, some of these biomolecules organize into structures not only unable to perform their biological function but in fact into toxic species with severe consequences in human health. In this context, the aggregation of the b-amyloid peptide is a hallmark of Alzheimer’s disease and has become a model system for the study of toxic aggregation pathways.1,2
In this project, we aim to develop and apply specifically tailored wide-field total internal reflection (TIR)3 and fluorescence correlation single-molecule fluorescence imaging methods (FCS)4 to investigate amyloid structure and dynamics in the presence of artificial lipid vesicles and supported lipid bilayers as models of the cellular membrane. The combination of both single-molecule approaches is particularly powerful as enables to interrogate the aggregation mechanism with temporal resolutions from microseconds to seconds in freely diffusing samples (Fluorescence Correlation Spectroscopy) and from milliseconds to minutes and even hours using surface-immobilized techniques (wide-field TIR). We will investigate the interaction of fluorescently labelled b-amyloid aggregates and other neurologically relevant proteins with lipid membranes at single-molecule level using protocols already developed in our team.
Eisenberg D, Jucker M (2012) The amyloid state of proteins in human disease. Cell, 148: 1188-1203.
Miller Y, Ma B, Nussinov R (2010) Polymorphism in Alzheimer Ab amyloid organization reflects conformational selection in a rugged energy landscape. Chem. Rev. 110: 4820-4838.
Roy, R. et al (2008) A practical guide to single molecule FRET. Nature Methods 5(6): 506
Haustein, E., Schwille, P. (2007) Fluorescence correlation spectroscopy: novel variations of a established technique. Ann. Rev. Biophys. Biomol. Struct. 36: 151
Single-molecule spectroscopy of conjugated polymers
This project combines two rapidly advancing fields of physics. One is the field of “plastic” semiconductors which are of interest for light-emitting diodes, solar cells and lasers. The other is single molecule spectroscopy in which light emission from a single molecule is studied. The aim of the project is to perform single-molecule measurements on semiconducting polymers in order to gain new insight into the light-emission process, and how it relates to the structure of the material. Single-molecule spectroscopy is particularly powerful for doing this because it enables the differences between individual molecules to be observed, whereas most measurements just average over many molecules. The project aims to observe and manipulate the structure and light-emission of individual polymer molecules in real time. This is in turn will lead to new understanding of how their properties relate to their structure that could lead to improved optoelectronic devices
http://www.st-andrews.ac.uk/physics/prosp_pg/phd/current_phd_projects.php?supv=jcp10&filter=1&button=Filter+by+Supervisor