Koimmunopipitaatio

Koimmunopipitaatio, also known as co-immunoprecipitation (Co-IP), is a common laboratory technique used to study protein-protein interactions. The method relies on the highly specific binding of an antibody to its target protein. In a typical Co-IP experiment, a specific antibody is used to 'pull down' a protein of interest from a complex mixture of cellular proteins. This antibody is usually immobilized on a solid support, such as agarose or magnetic beads, to facilitate separation.

The process begins with cell lysis, where the cells are broken open to release their proteins. The antibody, specific to one protein in a suspected complex, is then added to this lysate. If the target protein is present and is interacting with other proteins, these interacting partners will also be brought down when the antibody-protein complex is captured by the beads. After incubation, the beads are washed to remove any non-specifically bound proteins. The captured protein complex is then eluted from the beads.

The eluted material can be analyzed by various methods, most commonly by Western blotting, to identify the proteins that were co-precipitated with the target protein. This allows researchers to infer that these identified proteins were indeed interacting with the target protein in the cell. Variations of Co-IP exist, such as reciprocal co-immunoprecipitation, which can strengthen the evidence for an interaction. This technique is fundamental in molecular biology for mapping protein interaction networks and understanding cellular processes.