Structure and function in the brains of Alzheimer's

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A completely new approach to the study of Alzheimer's disease, initiated by a professor at the University of California, Santa Barbara, may solve a critical piece in the puzzle of the disease. This tragic neurological illness progressively erases memory in its millions of victims. The key to the new approach is understanding the way certain proteins in the brain fold, or rather "misfold."
Michael Bowers, a professor in the Department of Chemistry and Biochemistry, developed this project, which is being funded by the National Institutes of Health. Bowers is using specialized chemical research methods and applying them to biology. His research will depend upon the study of rare peptides, or strings of amino acids, that are difficult to produce. These will be provided by co-investigator David Teplow, a professor at UCLA's David Geffen School of Medicine, who has been involved in Alzheimer's research for over 10 years. Joan-Emma Shea, also a professor in UCSB's Department of Chemistry and Biochemistry, heads the theoretical modeling aspect of the project. He explained that now the hunt is on for the "small stuff." Because of their expertise in certain chemical methodologies, Bowers and his research group are able to track down the molecular level changes that lead to development of the disease.
The process of aggregation of proteins that cause the plaque begins in a way that Bowers has begun to clarify. The goal is to find non-toxic drugs that will interrupt the aggregation process. "If we can do that, we can stop the disease," said Bowers. "However, once you start losing neurons, things become very difficult, because the body doesn't readily replace them due to their very large size. If we could find a marker, early on, to indicate when the patient first has the disease, then the new drug or drugs that we hope to develop could prevent further damage." Bowers described his approach as a whole new way to determine the structure and composition of the Abeta 42 peptide and its oligomers that are primarily responsible for Alzheimer's disease. The research team is analyzing the way this peptide folds, causing it to aggregate and disrupt neuronal function.
The key aspect of ion mobility is its ability to measure accurate cross sections of complex aggregations of proteins and obtain information on their three-dimensional shape. When coupled with mass spectrometry, electrospray ionization, and high-level molecular modeling, it becomes a very powerful technique. The experiment starts with electrospray ionization, a method of spraying the solution containing the peptides of interest into fine droplets and then letting the droplets evaporate. Following evaporation, mass spectrometry is employed to determine the mass or weight of the species that were in the solution, and from that to determine the composition. Finally ion mobility is used to show the shape of the Abeta 42 peptide and its oligomers.