CubeServices Protein Characterization
Cube Biotech offers a comprehensive set of protein characterization methods to ensure structural integrity and functionality of the proteins produced in our service offering. We always provide a thorough discussion and counselling of your project, so that the methods used provide optimal analysis data for your protein of interest. Any service package can be booked on its own, or in conjunction with others. Learn more about our protein services.
1. Assessment of size and purity
All our projects include a characterization of the purified proteins by SDS-PAGE and Western Blot, using appropriate antibodies. We check for size, purity, potential degradation products, and presence of the affinity tag.
2. Ligand binding by SPR or ELISA
Surface plasmon resonance (SPR) measurements are used to determine ligand binding kinetics. In connection with the nanodisc technology, even highly flexible proteins such as GPCRs can be immobilized and stabilized during the measurement. Alternatively or in addition, ELISA-type experiments can be performed.
3. Protein-specific pulldown experiments
To identify the protein of interest, its conformation and ligand binding capability, we perform pulldown experiments with a protein-specific purification matrix that consists of agarose or magnetic beads carrying a specific binding partner for your protein. This step can also serve as (additional) purification step.
4. Assessment of structural integrity
Circular dichroism (CD) spectroscopy is performed to assess the protein's secondary structure. If applicable, tryptophane fluorescence can be measured to check for the environment of tryptophanes within the protein in the same vial, thereby minimizing the amount of material needed for analysis. Both measurements can be performed in the presence / absence of a specific ligand to monitor structural changes upon ligand binding. Measurements can be performed at different temperatures to monitor protein stability in different buffer / detergent conditions.
Stability of the proteins is assessed by thermofluor measurements to identify optimal buffer and detergent conditions for your protein.
6. Protein Activity Assays
For a more specific protein activity assay, established procedures can be reproduced in our lab to ensure the protein conforms to your standards. New protein assays can be developed if needed.