Plenarvorträge - DPG-Tagungen

Arbeitskreis Biologische Physik Dienstag
wavelength of their fluorescence, depend strongly on their size. Because
of their reduced tendency to photobleach, colloidal quantum dots are interesting
fluorescence probes for all types of labeling studies. We will give
an overview on how quantum dots so far have been used in cell biology.
In particular we will discuss the biological relevant properties of quantum
dots and focus on three topics: Labeling of cellular structures and receptors
with quantum dots, incorporation of quantum dots by living cells,
and the tracking of the path and the fate of individual cells by quantum
dot labels.
Hauptvortrag AKB 22.4 Di 15:30 H40
Detecting and Manipulating Single Molecules in the Fluid
Phase — •Petra Schwille — TU Dresden, Institut f. Biophysik
Single molecule research has within the past ten years become a fascinating
new approach in nearly all branches of physical sciences, but
for the biosciences it bears particular relevance: The ”key players” on
AKB 23 Membranes
a molecular scale - proteins - are remarkably complex and variable
molecules, their functionality in cells and organelles is so subtle that they
are often referred to as ”molecular machines”. To study these elaborate
molecular systems, traditional methods that analyze a certain function by
averaging over large ensembles are sometimes not appropriate: Especially
in the living cell, where a multitude of complex processes are continuously
occurring on a molecular scale, ensemble methods are unable to
capture the underlying mechanisms in a satisfactory manner. Techniques
that allow to study the distribution, translocation, interactions and internal
dynamics of single biological working units, in many cases single
protein molecules or complexes, are therefore of particular importance to
the biosciences. We discuss novel developments and applications of single
molecule-based dynamic analysis of proteins and nucleic acids in the living
cell, and give perspectives for possible strategies to manipulate, sort
and select single molecules in the fluid phase.
Zeit: Dienstag 16:30–18:00 Raum: H40
Hauptvortrag AKB 23.1 Di 16:30 H40
Microscopy and Spectroscopy on Single Membrane Proteins —
•Jörg Wrachtrup, Carsten Tietz, Margarita Khazarchyan,
and Thews Elmar — Universität Stuttgart, 3. Physikalisches Institut
The membrane environment is of vital importance for the function
of most cellular receptors. Either stability requires the lipid bilayer or
receptor function is related to oligomerisation in the membrane. The
contribution will describe single-molecule studies of photoreceptors in
membranes under ambient conditions as well as low temperature. Life
cell studies with fluorescence correlation sprectroscopy and burst width
analysis reveals clustering of TNF receptors as well as details of the diffusion
behaviour of second messengers in the apoptotic signalling pathway.
Hauptvortrag AKB 23.2 Di 17:00 H40
X-ray Scattering Studies of self-assembled Lipid Protein Membranes
— •Tim Salditt — Experimentalphysik, Universität des Saarlandes,
D-66041 Saarbrücken
AKB 30 Biomaterials and Bioengineering
Hauptvortrag AKB 23.3 Di 17:30 H40
Protein Micropatterns in Supported Lipid Membranes —
•Motomu Tanaka — Biophysics Lab, Tech. Univ. Munich
The design of soft, compatible interfaces between solids and biological
materials is an interdisciplinary challenge for scientific and biotechnological
applications. Planar cell surface models can be designed by deposition
of lipid membranes on ultrathin polymer supports that play the role of
extracellular matrix and glycocalix. As physical models of cell surfaces,
several methods have been developed to fabricate micropatterns of proteins
in supported membranes, such as (i) accumulation of membraneassociated
proteins by electrophoresis and (ii) confinement of proteins
in membrane micropatterns. The first method utilizes fluid supported
membranes as a quasi-2D matrix to separate membrane proteins under
lateral electrical fields, while the second includes the micropatterning of
biocompatible polymer supports. Such strategies are promising for complimentary
coupling of bioorganic functional systems and semiconductor
devices by matching of the lateral dimensions of biofunctional micropatterns
and device arrays.
Zeit: Mittwoch 14:30–16:30 Raum: H40
Hauptvortrag AKB 30.1 Mi 14:30 H40
Hierarchical Structure and Mechanical Function of Biological
Materials — •Peter Fratzl — Max Planck Institute of Colloids and
Interfaces, Department of Biomaterials, D-14424 Potsdam
Natural materials, such as tendon, bone, dentin, wood or mollusc shell
are hierachically structured and functional adaptation occurs at all size
levels. The aim of the newly created Department of Biomaterials at the
Max-Planck-Institute of Colloids and Interfaces is, first, to study structure
- function relations and the principles of mechanical deformation
and adaptation at all the hierarchical levels in natural materials. The
major approaches are in-situ deformation experiments with synchrotron
radiation or environmental scanning electron microscopy, scanning probe
techniques to obtain simultaneous structural and mechanical information
at several size levels, as well as numerical simulation. Second, different
approaches (”biomimetics” and ”biotemplating”) are being pursued in
order to transfer the principles of hierachical structuring to the development
of new materials for various applications. Third, research on bone
and connective tissue is carried out with the objective to characterize
the effect of diseases (such as the ”brittle bone disease”, for instance) as
well as to study the consequence of osteoporosis treatments on the bone
material quality.
Hauptvortrag AKB 30.2 Mi 15:00 H40
Bioelektronische Hybride — •Andreas Offenhäusser — Institut
f. Schichten und Grenzflächen (ISG-2), Forschungszentrum Jülich, 52425
Jülich
Unsere Forschungsaktivitäten konzentrieren sich auf die funktionelle
Kopplung biologischer Signalprozesse und Erkennungsreaktionen mit
mikro- und nanoelektronischen Halbleiterbauelementen. Hierbei werden
insbesondere folgende Systeme vorgestellt:
- Verwendung von Feldeffekt-Transistoren bei der Entwicklung eines
elektronischen DNA-Chips.
- Entwicklung von Ganzzell-Sensoren auf der Basis der Zell-Transistor-
Kopplung.
- Erzeugung lebender Nervenzell-Netzwerke zur Untersuchung der neuronalen
Informationverarbeitung.
Hauptvortrag AKB 30.3 Mi 15:30 H40
Micro- and Nanolithographic Tools for Designing Biophysical
Models of Cell Adhesion and Mechanics — •Joachim Spatz —
University of Heidelberg, Inst. Physical Chemistry, Biophysical Chemistry,
INF 253, 69120 Heidelberg
We investigate the dynamic regulation of adhesive contacts and of the
cytoskeleton architecture of cells in contact with novel nano- and microlithographic
materials, and its resultant influence on cellular activities
as well as clinical malfunctions in organism. In this context, we apply
new optical and mechanical techniques and develop new micro- and
nanostructured materials to perform experiments on living cells. We also
construct biomimetic models of protein networks with tuneable complexity
on nano- or microstructured platforms to untangle chemo-mechanical
properties of the cytoskeleton and the adhesion protein complex. In detail,
we will discuss (i) the development of nano- and microlithographic
interfaces by self-assembly and its biofunctionlisation, (ii) the activation
control of single integrin function of adherent cells by nanopatterned
adhesive interfaces, (iii) the biomimetic model design of the actin cortex
based on microfabricated pillar surfaces and dynamic holographic
optical tweezers, and (iv) a chemo-mechanical approach to understand
regulation of metastases formation of human cancer cells by cytoskeleton