MD-SIMULATION OF ALPHA-KERATIN INTERMEDIATE FILAMENTS

In recent years powerful computer systems have become readily accessib le to simulate complex chemical problems. Based on the primary structu re of the intermediate filament monomer unit of wool, small sequences are selected. Their molecular dynamic behaviour is simulated, in order to investigate the secondary and tertiary structure as well as their stability. The simulations are carried out for a helical segment and a linker segment, selecting the ideal alpha-helix as start conformation . In vacuum all simulations show an unstable alpha-helix due to shifts of the intrahelical hydrogen bonds. So a new helical structure with a larger helix diameter is formed. However in simulations with surround ing water the alpha-helix remains stable throughout the simulation tim e. Up to now it has not been possible to dectect any fundamental diffe rence in the molecular dynamic behaviour of the helical and the linker segment.