Biological_Process_Is_Part_Of_Process Molecular Interaction Process Protein-Protein Interaction C0872079 Protein-Protein_Interaction Protein-Protein Interaction C18469 Molecular Function Temporary, non-covalent binding between protein molecules. Protein-protein interactions occur as a result of intermolecular physical forces and spatial complementation between domains or motifs. This interaction can be either homotypic or heterotypic and effect protein structure, conformation, and function. Protein-Protein Interaction Biochemical Reaction