Institute of Complex Systems (ICS) Research in the Field of Biophysics and Soft Matter Interim Report (2009-2011) 1 Contents Introduction ....................................................................................................................... 4 ICS-1/JCNS-1: Neutron Scattering .................................................................................. 7 Research Highlights ..................................................................................................... 8 Functional domain dynamics of phosphoglycerate kinase.......................................... 8 Dynamics of poly(ethylene oxide) confined in AAO nanopores ................................ 10 Structure and dynamics of polymeric rings by neutron scattering............................. 12 Unified description of dielectric and viscoelastic long chain relaxation ..................... 14 Conformation of polymer chains in the presence of non-attractive nanoparticles..... 16 Ultrasoft colloid/polymer mixtures – making complex fluids look simple................... 18 ICS-2/IAS-2: Theoretical Soft Matter and Biophysics.................................................. 21 Research Highlights ................................................................................................... 22 Friction and rheology of star polymers in solution..................................................... 22 The hydrodynamics of micro-swimmers.................................................................... 24 Blood flow: Red-cell rheology and white-cell margination......................................... 26 Non-equilibrium polymer dynamics ........................................................................... 28 Polymers and colloids in micro-channels .................................................................. 30 Near-surface structure of micro-emulsions ............................................................... 32 Crumpling and collapse of thin elastic spherical shells ............................................. 34 Simulations of thermophoretic colloids...................................................................... 36 ICS-3: Soft Matter............................................................................................................ 39 Research Highlights ................................................................................................... 40 Near wall dynamics and particle wall interaction in flowing suspensions.................. 40 Probing the (hydro-) dynamic interactions of tunable colloidal rods.......................... 42 Non-equilibrium states and dynamics in concentrated dispersions of charged rod-like colloids in electric fields............................................................................................. 44 Thermal diffusion of stiff rod-like mutant Y21M fd-virus ............................................ 46 High pressure microscopy cell up to 100MPa........................................................... 48 Dynamics and phase behaviour of dispersions of proteins and colloids................... 50 ICS-4: Cellular Biophysics ............................................................................................. 53 Research Highlights ................................................................................................... 54 HCN1 channels are essential for regular mesopic cone vision................................. 54 HCN channels are differentially expressed in the olfactory system .......................... 56 Control of cellular Ca2+-signaling by a biogenic amine receptor ............................... 58 Serotonin’s role in controlling the phototactic behavior of honeybees ...................... 60 Super-resolution microscopy – PALM and dSTORM................................................ 62 FRET-based genetically encoded biosensors........................................................... 64 ICS-5: Molecular Biophysics.......................................................................................... 67 Research Highlights ................................................................................................... 68 Native and unfolded states of PGK studied by single-molecule FRET ..................... 68 Membranes: Mechanisms of signal propagation and proton transport ..................... 70 Membrane protein diffusion and interactions studied by 2f-FCS .............................. 72 Force measurements using optical tweezers............................................................ 74 Method and process development for membrane protein analysis........................... 76 Biophysical studies on the arrestin activation mechanism ........................................ 78 X-ray holography in biology....................................................................................... 80 ICS-6: Structural Biochemistry...................................................................................... 83 Research Highlights ................................................................................................... 84 Structural basis of cyclic nucleotide-activated ion channel gating ............................ 84 Interaction between human CD4 and HIV-1 protein VpU ......................................... 86 GABARAP-like proteins – autophagy and beyond.................................................... 88 2 Protein structure determination at low resolution ...................................................... 90 Approaches for therapy of Alzheimer’s disease........................................................ 92 Simulation studies of the Alzheimer’s peptide Aβ .................................................... 94 Surface-FIDA: single particle detection as diagnostic tool ........................................ 96 ICS-7: Biomechanics .................................................................................................... 101 Research Highlights ................................................................................................. 102 Cyclic Stress at mHz frequencies aligns cells in direction of zero strain................. 102 Shape normalization as a tool to quantifify typical cell behaviour ........................... 104 Filopodia as key feature for early migratory processes........................................... 106 Presenilin affects focal adhesion site formation via c-Src ....................................... 108 Probing bio-membrane dynamics with microinterferometry .................................... 110 Tube width fluctuations in F-actin solutions............................................................. 112 Novel fusogenic liposomes for in vivo fluorescent cell labelling.............................. 114 ICS-8/PGI-8: Bioelectronics.......................................................................................... 117 Research Highlights ................................................................................................. 118 Axon guidance of rat cortical neurons by microcontact printed protein gradients... 118 Light induced stimulation and delay of cardiac activity............................................ 120 Nanoelectronic devices for direct communication with cells ................................... 122 Development and characterization of carbon nanotube sensors ............................ 124 Nanotechnology tools for cell-chip communication ................................................. 126 Electrochemically transduced logic gate on molecular level ................................... 128 Intermolecular electron transport investigated by break junctions .......................... 130 Strained SrTiO3 films on sapphire ........................................................................... 132 Low field magnetic resonance imaging with tuned high-Tc SQUID ......................... 134 Education, Dissemination, Workshops and Conferences ........................................ 136 International Helmholtz Research School on Biophysics and Soft Matter .............. 137 Centre for Structural Biology and Helmholtz Nanoelectronic Facility II................... 139 42nd IFF Spring School 2011: Macromolecular systems in soft and living matter.. 141 The Jülich Soft Matter Days .................................................................................... 143 1st BioScience Workshop 2010: Expanding the frontiers of biomolecular science. 145 Publications................................................................................................................... 148 ICS-1/JCNS-1 ............................................................................................................. 148 ICS-2/IAS-2................................................................................................................. 153 ICS-3 ........................................................................................................................... 159 ICS-4 ........................................................................................................................... 162 ICS-5 ........................................................................................................................... 164 ICS-6 ........................................................................................................................... 168 ICS-7 ........................................................................................................................... 172 ICS-8/PGI-8................................................................................................................