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AKB: Biologische Physik
AKB 50: Poster Session "Biological Physics"
AKB 50.97: Poster
Freitag, 12. März 2004, 10:30–13:00, B
FCS used to study translational mobilities in plasma membranes of living cells — •Margarita Khazarchyan1, Elmar Thews1, Carsten Tietz1, Jörg Wrachtrup1, Sylvia Willi2, Anja Krippner-Heidenreich 2, and Peter Scheurich2 — 13.Physikalisches Institut, Universität Stuttgart, Pfaffenwaldring 57, 70569 Stuttgart — 2Institut für Zellbiologie und Immunologie, Universität Stuttgart, Allmandring 31, 70569 Stuttgart
Fluorescence correlation spectroscopy (FCS) is an attractivce method of measuring molecular concentrations, chemical kinetics and diffusion processes in living cells. We use one- and two-photon excitation for the investigation of translational mobility in cytoplasm and in plasma membranes using different fluorophores for intracellular applications of FCS. Measurements in living cells and in plasma membranes are feasible with reasonable signal-to-noise ratios, even with fluorophore concentrations on a single molecule level in the detection volume.
We present an application of this method to study TNF(Tumor Necrosis Factor)-R1, TNF-R2 in plasma membranes and TRAF2-protein in cytoplasm of living cells. Other investigations demonstrated that TNF-R and TRAF-proteins involved in the cells apoptotic pathway. Apoptosis is the specific controlled mechanism of cell death which is distinct from uncontrolled necrotic cell death. Apoptosis requires tight regulation. Lack of such regulation leads to either too much or too little apoptosis, resulting in pathological conseqeunces, such as Alzheimer disease or cancer.
Diffusion coefficients of the signal TNF-R and TRAF2-protein were determined before and after stimulation with TNF ligand.