PhD student in the the group of Prof. Hermann Gaub, LMU Munich
Associate Intern at McKinsey & Company for three months
2007 - 2008
Diploma thesis in the group of Prof. Hermann Gaub, LMU Munich
Topic of Diploma Thesis: "Differential Force Measurements on DNA and RNA - Analysis of the affinity of aptamers to their ligands"
Working Student at the MPI for Psychiatry in the group of Prof. Hans-Ulrich Dodt about ultramicroscopy of biological probes
2005 - 2006
Graduate Student at Boston University, Boston, MA;
Scholarship of the IDK-NBT (Elitenetwork of Bavaria)
2005 - 2008
Scholarship of the Max-Weber-Program (Elite network of Bavaria)
2005 - 2006
scholarship of the German-American Fulbright Foundation
2002 - 2005
BayBFG of the Bavarian government
Comparative force measurements test the binding strength of two molecular complexes in series against each other and are very sensitive to small changes of the bond stability. This principle is realized in the Comparative Unbinding Force Assay (CUFA) that enables the detection of a single mismatch in a 20 base pair DNA duplex.
In my diploma thesis, I implemented aptamers, small nucleic acids that bind their ligand with a specificity rivaling that of antibodies, in the assay and analyzed their binding behavior to their ligand. The formation of the ligand-aptamer complex leads to a reorganization of the structure and to an increase of the mechanical stability, which allows detection and determination of the dissociation constant. The multiplexing capabilities of the current assay enables the measurement of 16 different systems on one chip and makes the application of force-based aptamer sensors in diagnostics possible.
For my PhD project, I want to analyze the binding and cleaving behavior of the protein dicer. Dicer binds unspecifically to double-stranded RNA molecules and cuts them into pieces of 19-22 bp of length. Since dicer also cleaves microRNA-molecules from their precursor molecule, a process called maturation of the microRNA, it plays an essential role in eukaryotic cells. MicroRNAs are short single-stranded RNA molecules (around 20 bp) that can bind to mRNAs without complete complementarity and, hereby, influence protein translation. I now analyze the binding of small molecules to double-stranded RNA and see if these small molecules can hinder Dicer from binding and especially cleaving the RNA, thus preventing the maturation of the microRNA. Such small molecules are of interest to drug development.
D. Ho, K. Falter, P. Severin, H. E. Gaub:
"DNA as a force sensor in an aptamer-based biochip for adenosine"
Anal. Chem., 81 (8), pp 3159–3164 (2009)
D. Ho, C. Dose, C. H. Albrecht, P. Severin, K. Falter, P. B. Dervan, H. E. Gaub:
“Quantitative detection of small molecule/DNA complexes employing a force-based and label-free DNA-microarray”
Biophys J. 2009 Jun 3;96(11):4661-71 (2009)
D. Ho, J. L. Zimmermann, F. A. Dehmelt, U. Steinbach, M. Erdmann, P. Severin, K. Falter, H. E. Gaub:
"Force-driven separation of short double stranded DNA"
Biophysical Journal. 97:3158-3167 (2009)