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Hendrik Schroeder

Publications and source records attributed to Hendrik Schroeder.

4 recordsLinked to original sources

A generic building block for C- and N-terminal protein-labeling and protein-immobilization.

Expressed protein ligation (EPL) and bioconjugation based on the maleimide group (MIC-conjugation) provide powerful tools for protein modification. In the light of the importance of site-selectively modified proteins for the study of protein function, a flexible method for the introduction of tags and reporter groups into the C-terminus of proteins employing EPL and MIC-conjugation was developed. We describe the solid-phase synthesis of a generic building block, equipped with fluorescence markers or different functional groups. This generic building block allows for a flexible incorporation of different tags into proteins and was used for the introduction of fluorescence markers into the C-terminus of Rab and Ras GTPases by EPL or MIC-conjugation techniques. In addition, a building block appropriately modified for the incorporation of an azide into proteins was synthesized. Azide-functionalized Ras protein was immobilized on a phosphane-modified surface by means of Staudinger ligation providing a highly chemoselective ligation method for the immobilization of proteins.

Azides↗

Design and evaluation of single-stranded DNA carrier molecules for DNA-directed assembly.

Due to the exceptional molecular recognition properties of nucleic acids, the computational design of DNA sequence motifs is of paramount interest for a wide variety of applications, ranging from DNA-based nanotechnology and DNA computing to the broad field of DNA microarray technologies. These applications rely on the specificity of Watson-Crick base-pairing, and thus, are highly sensitive to non-specific interactions and the formation of any undesired secondary structures, which contradict an efficient intermolecular hybridization. Here we report on the in silico design and in vitro evaluation of single-stranded DNA (ssDNA) carrier strands for the directional DNA-based positioning of streptavidin (STV) conjugates covalently tagged with short ssDNA oligonucleotides. Each such carrier strand consists of four hybridization sites complementary to the conjugate DNA strands. The high and homogeneous hybridization efficiency measured in vitro by microarray hybridization assays confirms the quality of our in silico sequence design method. Hybridization efficiency of DNA-STV-conjugates depends on the position of the hybridization site in the carrier sequence, where the positions nearest to and farthest from the microarray surface proved to be most favorable.

Carrier Proteins↗

Microarray-based in vitro evaluation of DNA oligomer libraries designed in silico.

We report on the microarray-based in vitro evaluation of two libraries of DNA oligonucleotide sequences, designed in silico for applications in supramolecular self-assembly, such as DNA computing and DNA-based nanosciences. In this first study which is devoted to the comparison of sequence motif properties theoretically predicted with their performance in real-life, the DNA-directed immobilization (DDI) of proteins was used as an example of DNA-based self-assembly. Since DDI technologies, DNA computing, and DNA nanoconstruction essentially depend on similar prereguisites, in particular, large and uniform hybridization efficiencies combined with low nonspecific cross-reactivity between individual sequences, we anticipate that the microarray approach demonstrated here will enable rapid evaluation of other DNA sequence libraries.

Base Sequence↗