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Special methodical expertise

enzyme gene identification – metagenomics
protein expression systems
large-scale (fermenter) protein production and purification
protein engineering and directed evolution
photochemistry of photoreceptor proteins

• Novel genes can be isolated from environmental samples directly, i.e. without prior cultivation of the repective organisms. This approach termed metagenomics enables molecular biologists to access natural biodiversity.
• Genes as such aren't useful unless researchers succeed to express them, i.e. translate genetic information (found in the gene) into a functional protein which can subsequently be characterized both scientifically and for potential biotechnological application. Hence, we use existing and develop novel bacterial strains for expression of novel genes.
• After successful expression, the respective proteins must be produced at larger scales to allow biochemical charactrization, structure determination, and application studies. To this end, we can provide large scale fermentations in automated biorectors of up to 40 liter volume. Various methods are used for protein characterization including enzyme activity assays, automated chromatography, high-performance liquid chromatography (HPLC)- and gas chromatography (GC) analytics, optical (UV/VIS and fluorescence)- and circular dichroism (CD) -spectroscopy.
• Proteins and, in particular, enzymes often need to be tailored for specific needs. This can be done either by rational protein design or by using a variety of molecular biological methods termed "directed evolution". We have established these methods in our laboratory and can thus arm our proteins with desired properties.
• Photoreceptors sense light. In order to do so, they contain a light-absorbing co-factor, the so-called chromophore that is bound within the photoreceptor protein. This chromophore absorbs photons of a specific wavelength of light and in turn triggers protein conformational changes which itself then initiate a biological response. We use optical spectroscopy techniques to elucidate the structure-function relationships of photoreceptors and their respective chromophores.




Figure:
A: Bacterial cultures grown under blue-light illumination
B: Automatic bioreactor for the large-scale production of heterologous proteins
C: Liquid-handling robot used for high-throughput screening
D: Colony-picking robot
E: Purified LOV-protein emitting bright yellow-green fluorescence after excitation with blue-light.