Proteins are central molecules regulating our lives. Mimicking the functions of proteins provides important clues to not only developing functional and pharmaceutical materials but also understanding the mechanistic structure-function relationships. Proteins localizing in the cytosol, membrane, and extracellular media have distinct chemical properties and biological roles, which closely relate to intractable diseases. We focus on developing synthetic mimics of these proteins based on the viewpoints of supramolecular chemistry for pharmaceutical applications.