CONFOCHECK

The CONFOCHECK is a dedicated FTIR system for the investigation of proteins in water. Its specific configuration facilitates a fast data acquisition (ca. 30 sec. per sample) with a high sample throughput controlled by an extremely user-friendly software interface.

FTIR Protein Applications

• Protein quantification

• Detection of conformational changes

• Protein dynamics (temperature induced conformational changes)

• Monitoring of conformational changes during protein aggregation, precipitation and crystallization

• Determination of the secondary structure

• Quantification of all kind of solutes in aqueous samples (buffers, excipients, detergents)

Typical Applications in Pharma:

• Pre-formulation and formulation development: Analysis of the influence of the formulation on protein stability

• Stability studies (stress tests): Influence of pH, temperature, mutation, etc. on the protein stability

• Quality control: Check of protein concentration, structure on correct product composition (buffer, excipients) in production environment

• Binding studies: Analysis of the impact of ligand-binding on the protein structure

Main applications for the CONFOCHECK are the detection and quantification of conformational changes in proteins and the protein concentration determination. Quantitative determination of the protein concentration and the secondary structure elements (alpha-helix, beta-sheet) from the analyzed protein samples is accomplished within seconds via internal calibrations. The CONFOCHECK is equipped with several specific protein sampling cuvettes that allow the measurement of solved and membrane bound proteins, even at very low amounts (10 µg). To reach optimal temperature constancy and to facilitate the measurement of temperature induced protein conformational changes, the sample cuvettes are temperature-controlled by a thermostat.

The AquaSpec^TM is used for the measurement of water soluble proteins or solubilised membrane-bound proteins. This cuvette is a flow-through transmission cell, with a path length of about 7 µm, which is optimal for the measurement of aqueous samples. In comparison to conventional cuvettes the AquaSpec^TM cell permits a high sample throughput. Furthermore, a much higher accuracy is achieved, allowing the measurement of low protein concentrations (below 0.1 mg/ml) and the detection of smallest conformational changes. Using the internal calibrations of the CONFOCHECK the secondary structure and concentration of the analyzed protein are determined directly after measurement (ca. 30 sec.).

Temperature-induced unfolding / refolding processes are studied by the BioATRCell II. This unit facilitates the automized measurement of temperature ramps (0-95°C) from which the specific changes of the secondary structure and the protein melting point can be determined. Also processes like fibrillation and aggregation can be followed and analyzed. To monitor protein structural changes in dependence of ph changes or ligand-binding, a special dialysis top section is available for the BIOATRCell II. Here, low molecular weight substances can be dialyzed into the protein compartment without diluting the protein.