Technische Universitat Berlin 4 articles published in JoVE Bioengineering Residue-Specific Exchange of Proline by Proline Analogs in Fluorescent Proteins: How "Molecular Surgery" of the Backbone Affects Folding and Stability Tuyet Mai Thi To1, Vladimir Kubyshkin2, Franz-Josef Schmitt3, Nediljko Budisa1,2, Thomas Friedrich1 1Institute of Chemistry, Technische Universität Berlin, 2Department of Chemistry, University of Manitoba, 3Institute of Physics, Martin-Luther-Universität Halle-Wittenberg To overcome the limitations of classical site-directed mutagenesis, proline analogs with specific modifications were incorporated into several fluorescent proteins. We show how the replacement of hydrogen by fluorine or of the single by double bonds in proline residues ("molecular surgery") affects fundamental protein properties, including their folding and interaction with light. Bioengineering In Situ Microscopy for Real-time Determination of Single-cell Morphology in Bioprocesses Anna Maria Marbà-Ardébol1, Joern Emmerich2, Michael Muthig2, Peter Neubauer1, Stefan Junne1 1Chair of Bioprocess Engineering, Department of Biotechnology, Technische Universität Berlin, 2SOPAT GmbH A photo-optical in situ microscopy device was developed to monitor the size of single cells directly in the cell suspension. The real-time measurement is conducted by coupling the photo-optical sterilizable probe to an automated image analysis. Morphological changes appear with dependence on the growth state and cultivation conditions. Biology Residue-specific Incorporation of Noncanonical Amino Acids into Model Proteins Using an Escherichia coli Cell-free Transcription-translation System Emanuel G. Worst1, Matthias P. Exner2, Alessandro De Simone2, Marc Schenkelberger1, Vincent Noireaux3, Nediljko Budisa2, Albrecht Ott1 1Department of Experimental Physics, Saarland University, 2Institute of Chemistry, Technische Universität Berlin, 3School of Physics and Astronomy, University of Minnesota An easy-to-use, cell-free expression protocol for the residue-specific incorporation of noncanonical amino acid analogs into proteins, including downstream analysis, is presented for medical, pharmaceutic, structural and functional studies. Engineering A Cost-effective and Reliable Method to Predict Mechanical Stress in Single-use and Standard Pumps Ina Dittler1, Wolfgang Dornfeld2, Reto Schöb2, Jared Cocke3, Jürgen Rojahn3, Matthias Kraume4, Dieter Eibl1 1Institute of Biotechnology, School of Life Sciences and Facility Management, Zurich University of Applied Sciences, 2Levitronix Ltd., 3SOPAT Ltd., 4Institute of Chemical and Process Engineering, Technische Universität Berlin Shear stress investigations on an oil-water emulsion system result in drop breakup over the experimental time. To count drop sizes in pumping processes, the suitability of inline endoscopy was successfully demonstrated in this protocol.
