Dresden 2006 – wissenschaftliches Programm

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CPP: Chemische Physik und Polymerphysik

CPP 12: POSTER Colloids, Nanoparticles and Self-Organizing Systems

CPP 12.19: Poster

Dienstag, 28. März 2006, 17:00–19:00, P3

Effects of the bead–surface interaction on the restricted rotational dynamics of nonrigid immobilized macromolecules. — •Alexander Uvarov and Stephan Fritzsche — Universität Kassel, D–34132 Kassel, Germany

Many problems in biophysics involve the rotational motion of macromolecules which immersed in solution. Well–known examples refere to dielectric relaxation, nuclear magnetic relaxation as well as to the nd depolarization of the fluorescence light. During the past decade, therefore, a large number of experiments and dynamic simulations (DS) have been carried out in order to describe the rotational properties of biomolecules. Apart from free macromolecules in solution, some experiments also concerned the restricted mobility of macromolecules which are immobilized on a surface and which are interpreted in terms of their molecular subsystems, the so–called beads of the macromolecule [1].

In the present contribution, we explore the question of how the bead–bead as well as bead–surface interaction affects the (restricted) rotational diffusion of molecules immobilized at a surface. Making use a recently derived Diffusion equation [1], we performed detailed computations for the orientational correlation functions and the rotational diffusion coefficient of the macromolecule for several types of the bead–bead and bead-surface interaction potentials. Results from our theory will be compared with other computations including the Brownian DS of the macromolecule [2].

[1] A. Uvarov and S. Fritzsche, J. Chem. Phys. 121, 6561, (2004)

[2] B. Carrasco, G. de la Torre, Biophys. Journal 75, 3044, (1999).