Berlin 2008 – wissenschaftliches Programm

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BP: Fachverband Biologische Physik

BP 26: Posters II

BP 26.48: Poster

Donnerstag, 28. Februar 2008, 17:00–19:30, Poster A

Formation of Domains in Bacterial Flagella — •Reinhard Vogel and Holger Stark — Institute for Theoretical Physics, TU Berlin, Germany

Many types of bacteria swim by rotating a bundle of helical filaments also called flagella. Each filament is driven by a rotatory motor. When its sense of rotation is reversed, the flagellum leaves the bundle and undergoes a sequence of configurations characterised by their pitch, radius and helicity (polymorphism). Finally the flagellum assumes its original form and returns into the bundle.

In general, the helical shape of the bacterial flagellum can assume 11 different configurations depending e.g. on mechanical loading, temperature and chemical composition of the solution. In recent optical tweezer experiments, Darnton and Berg [1] pulled at the flagellum and induced transformations between different helical configurations but they also observed the simultaneous occurrence of two configurations separated by a transition region. We investigate this domain formation based on the helical Kirchoff-rod model and the Calladine model [2] for the bacterial flagellum and present first results of our theoretical study.

[1] N.C.Darnton H.C. Berg, Biophys. J. 92, 2230-2236 (2007)

[2] C.R. Calladine,Nature (London) 255, 121 (1997)