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CPP: Chemische Physik und Polymerphysik
CPP 8: Biological Systems
CPP 8.3: Talk
Wednesday, April 4, 2001, 16:25–16:45, 111
ATR-SPP-UV-Ramanspectroscopy as a Sensitive and Selective Tool for Conformational Analysis of Biological Molecules — •D. Zerulla, G. Isfort, K.-D. Schierbaum, D. Riesner, and A. Otto — Heinrich-Heine-Universität Düsseldorf, AG Physikalische Methoden für Biologie und Medizin, Universitätsstr. 1, D-40225 Düsseldorf, Germany
The analysis of the molecular, conformational changes gives new
insights to the understanding of biological processes. Especially in
the field of infectious protein diseases like BSE, Scrapie and CJD, it
is important to understand the underlaying structural mechanisms of
folding
on a molecular level. In order to get information from relevant
biological
systems by a more physical-spectroscopic approach the method needs to be
very sensitive (as infectious molecules are difficult to get in high
concentrations from in-vivo systems) and extremely selective (in order
not to
get confused by the numerous other proteins and macromolecules).
Our method of choice is the ATR-SPP-Ramanspectroscopy, which fulfills,
in
combination with elaborate setups, all above mentioned criteria plus it
works
without any need for labeling.
The high sensitivity is given by a surface enhanced process:
A surface-plasmon-polariton is specifically excited in a thin (10nm),
evaporated Al-film. Its evanescent EM-field causes amplified
Raman-scattering
within 100nm from the Al-surface. The high selectivity is caused by
resonant
excitation of the π−π*-transition of the peptide-bonding at
206.5nm.
Because of the resonance effects neither the aqueous matrix nor other
non-amino molecules disturb the spectra.