Biochemical Tweezers - Molecular Organization of Proteins on Surfaces

Ali Tinazli1, Jilin Tang1, Ramunas Valiokas1, Srdjan Picuric1, Suman Lata1, Jacob Piehler1, Bo Liedberg2, and Robert Tampé1 1Institute of Biochemistry, Biocenter, Marie-Curie-St. 9, D-60439 Frankfurt/Main, Germany 2Sensor Science and Molecular Physics Group, Dept. of Physics and Measurement Technology, Linköping University, S-58183 Linköping, Sweden e-mail: tinazli@stud.uni-frankfurt.de URL: http://www.biochem.uni-frankfurt.de

Biocompatible surfaces suitable for specific and functional tethering of proteins in a functional manner are key prerequisite for studying molecular processes on surfaces and molecular organization of biomolecules.

Here we present the design and synthesis of an OEG alkyl thiol functionalized with a multivalent chelator as biochemical tweezers, which forms together with a matrix OEG alkyl thiol, mixed self-assembled monolayers (SAMs) on gold surfaces. These SAMs were characterized extensively by various surface physical techniques. Experiments by surface plasmon resonance (SPR) and atomic force microscopy (AFM) show that these surfaces are biocompatible and allow specific tethering of functional proteins with high affinity in a reversible and switchable manner. Patterning of surfaces with these chelating compounds via micro-contact printing (µCP) and analysis by chemical force microscopy illustrates the switchable and reversible properties of these chelating SAMs. Scanning probe-based lithography techniques allow a nanoscaled organization of proteins for fabrication of protein arrays. Fluorescence microscopy enables an efficient read-out of these protein arrays.

These presented surfaces allow switchable long-term immobilization of proteins and constitute a platform for solid-phase-based biophysical methods as for example SPR, AFM or fluorescence microscopy. Lateral organization of proteins is performed by µCP and scanning-probe-based lithography.