The Molecular Interaction Analysis laboratory provides various protein analysis services to St. Jude investigators and staff. Proteins are made up of a chain of amino acids. At each position in the chain any one of 20 amino acids may be present. Protein sequencing by Edman degradation is available to determine the sequence of the amino acids at each position in the chain.
Protein-Protein interactions are measured by Surface Plasmon Resonance using a Biacore 3000 instrument. Proteins exhibit specific interactions with other proteins. These interactions can be necessary for one protein to act on another or for the formation of a multi-protein complex in which the proteins function cooperatively. The stability of these complexes and the rates at which they form are important to understanding how they function. Identification of the sites within the complex responsible for these interactions can provide information of how they form. These interactions can be studied by attaching one of the proteins to a surface and flowing a solution of the other protein over the surface. Measurements of the rate at which the protein in solution is concentrated on the surface and how tightly it is held there provide information on the stability and rate of formation of complexes between the two proteins. The sites in the protein involved in the binding can be identified by measuring the binding of a series of peptides representing pieces of the protein to the surface. The peptides that bind to the surface contain the region of the protein required for the binding interaction.
Services
Please stop by room DT1011, call extension 4845, or email one of our staff if you have questions or concerns.
- Protein Interaction Analysis
Protein Interaction analysis is provided using a Biacore 3000. Interactions of proteins with other proteins, nucleic acids, small molecules or even whole cells can be detected. Measurements of kinetic rate constants, equilibrium binding constants (kon and koff), relative binding affinity (KD) or measurements of active protein concentrations are possible. - Equilibrium Dialysis
Equilibrium dialysis is provided for the measurement of the equilibrium dissociation constant, KD, between a protein and a small molecule such as a drug or metabolite. Detection is typically by the use of a radioactively labeled small molecule but other detection methods are possible in some cases.