Regensburg 2010 – wissenschaftliches Programm
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BP: Fachverband Biologische Physik
BP 7: Posters: Biological Machines, Motor Proteins
BP 7.3: Poster
Montag, 22. März 2010, 17:15–20:00, Poster B1
Cooperative effects in the inhibition of a Kinesin-5-head/Kinesin-1-stalk chimera by monastrol — Stefan Lakämper1,2,3, Christina Thiede1, •André Düselder1, Stefanie Reiter1,3, Lukas C. Kapitein2,4, Erwin J.G. Peterman2, and Christoph F. Schmidt1,2,3 — 1Drittes Physikalisches Institut, Georg-August-Universität Göttingen, Germany — 2Department of Physics and Astronomy and Laser Centre, VU University Amsterdam, The Netherlands — 3DFG-Research Centre for Molecular Physiology of the Brain, CMPB, Göttingen, Germany — 4Current address: Erasmus University Medical Centre, Rotterdam, The Netherlands
Several kinesin motors are required for proper assembly of the mitotic spindle. The homo-tetrameric bipolar Kinesin-5 can cross-link and slide antiparallel microtubules apart by a motility mechanism comprising diffusional and directional motility. In order to explore the basic kinesin-5 motor activity, we generated a stably dimeric Kinesin-5 construct, Eg5Kin, consisting of motor domain and neck-linker of Xenopus laevis Kinesin-5 and neck coiled-coil of Drosophila melanogaster Kinesin-1. This chimera is highly processive. We studied the effect of the Kinesin-5-specific inhibitor monastrol in single-molecule fluorescence assays. In order to find out if one or two monastrol molecules terminate a run, we analyzed the monastrol concentration dependence of the motor run length. We found a Hill coefficient of about 2. We discuss in how far this means that two monastrols need to be bound to create an effect and what kind of cooperativity this implies for binding of monastrol to the two heads of a motor dimer.