Protein binding refers to the process by which proteins interact with other molecules, such as ligands, substrates, or other proteins. These interactions are crucial for various biological processes, including signaling pathways, enzymatic reactions, and transport of molecules within the cell. Protein binding can be reversible or irreversible, depending on the strength of the interaction between the protein and the ligand. Understanding protein binding is essential for drug development, as many drugs exert their effects by binding to specific proteins in the body. Researchers study protein binding to gain insights into the mechanisms by which proteins interact with other molecules and to identify potential targets for therapeutic intervention.