Amphiphile monolayers as models to study polyelectrolyte coupling and enzyme reactions at membrane surfaces

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Helmuth Moehwald Sr., Interfaces, Max-Planck-Institute of Colloids and Interfaces, Campus Golm, Potsdam, 14424, Germany and Gerald Brezesinski, MPI of Colloids and Interfaces, Am Mühlenberg 1, Potsdam, 14424, Germany.
Amphiphile Monolayers as models to study polyelectrolyte coupling and enzyme reactions at membrane surfaces H. Möhwald, G. Brezesinski Max-Planck-Institute of Colloids and Interfaces D-14424 Potsdam, Germany Phospholipid monolayers have frequently been discussed as membrane models, but their real strength exists in studying interactions occurring at membrane surfaces. This basically concerns interactions with natural and synthetic polyelectrolytes and enzymatic reactions with phospholipid participation. Modern techniques of monolayer characterization (X-ray diffraction, opt. microscopies, FTIR spectroscopy) have additionally enabled one to study structures and processes in detail. In this contribution we will demonstrate that -the activity of phospholipases depends on the monolayer structure, for different lipases in different ways. -Reaction products change the monolayer structure which may lead to an indirect inhibition which is of long range and cooperative -Stiff polyelectrolytes like DNA order at interfaces and in turn order the lipid monolayer