Ray R. Irani Hall
Molecular and Computational Biology
Computational Biology Colloquium
Martin Beck
European Molecular Biology Laboratory
Heidelberg, Germany
"Molecular Anatomy of the Human Pathogen
Leptospira interrogans"
Abstract:
Systems biology conceptualizes biological systems as dynamic networks of interacting elements, whereby functionally important properties are thought to emerge from the structure of such networks. Due to the ubiquitous role of complexes of interacting proteins in biological systems, their subunit composition and temporal and spatial arrangement within the cell are of particular interest. Here we have combined quantitative mass spectrometry and cryo electron tomography to detect, count and localize specific protein complexes within the cytoplasm of the human pathogen Leptospira interrogans. We employed statistical concepts established for assigning fragment ion spectra to peptide sequences in mass spectrometry based proteomics to increase and quantify the confidence in assigning cryo electron microscopy signals acquired by tomography of intact L. interrogans cells to templates representing a range of stable, cellular protein complexes. Using this combined mass spectrometry and cryo electron tomography strategy we investigated the response of L. interrogans to antibiotics-treatment. We observed that the bacterial stress response system reacted with significant quantitative change and spatial rearrangement within the cell for some of the observed complexes. The described hybrid approach combines the strength of mass spectrometry to identify and quantify specific cellular proteins with the capability of cryo electron tomography to observe single protein complexes under close to live conditions, and allows observing the cellular proteome in space and time.
FRIDAY, February 12, 2010
12:00 pm
RRI 101
Host: Frank Alber
