Proteomics

After the successful human genome project provided almost endless information about possible sequences of proteins, Proteomics will have to provide the means to create, analyze and to understand structure and function relationships of these many proteins. Fourier Transform Infrared spectroscopy has contributed to protein structure analysis in the past but was not very attractive to many researchers, since it cannot reveal a 3D picture of the protein structure in contrast to X-ray crystallography and NMR spectroscopy. However, the restrictions of the latter methods (the need of crystals or small water-soluble proteins) provide infrared methods with a serious advantage. Using IR spectroscopy proteins can be studied in aqueous solution regardless of their molecular weight. Moreover, IR is capable to reveal conformational changes from solved proteins with very high sensitivity. It is therefore a very suitable tool for the control of protein stability or for the monitoring of induced unfolding/refolding processes.

CONFOCHECK is a dedicated and compact FT-IR system for fast and easy determination of protein secondary structure. Its specific configuration facilitates a fast data acquisition with a high sample throughput controlled by an user friendly software interface. Within fractions of a minute, high quality spectra from proteins in solution are acquired. Afterwards, quantitative determination of secondary structure elements ( a-helix, ß-sheet) from the analyzed protein samples is accomplished within seconds via pattern recognition methods based on a growing protein spectra library. CONFOCHECK is also designed to follow temperature induced protein conformational changes by FT-IR. Therefore, an integrated cooling thermostat modulates the temperature at the internal Bio-ATR II accessory very accurately. Automatically, measurements are recorded for the specified temperature range with a selected increment, whereby the water vapor is subtracted from the received spectra subsequently.

Using the AquaSpec flow through transmission protein stability can be tested on native proteins, under different pH and salt conditions, after introducing mutations or for storage dependencies. In addition, protein-protein, protein-DNA, protein-substrate and protein-ligand binding can be studied. Additional capabilities for protein interaction studies are provided by the Bio-ATRcell I which is especially designed for online dialysis. This accessory, which is completely compatible with the hardware and software from CONFOCHECK allows to apply low molecular weight compounds to the protein of investigation by dialysis. The dialysis membrane feature is essential as it avoids protein dilution during the experiment. Typically, the experimental results show detailed molecular information from the protein/ligand during interaction.

Unrestricted secondary structure analysis and classification of proteins.
Thermal and chemical stability of proteins.
Protein concentration determination
Study of protein-protein and protein-ligand interactions
Monitoring denaturation (unfolding), refolding and aggregation of proteins.