A protein is a large molecule comprised of a long chain of amino acids that is folded into a three-dimensional shape. The specific amino acid sequence and 3-D shape determines the biological function of the protein. Technically, any protein-based drug is a “therapeutic protein,” but the term was first used to describe medicines that are genetically engineered versions of naturally occurring human proteins.
Therapeutic proteins can be used to replace a protein that is abnormal or deficient in a particular disease. They can also augment the body’s supply of a beneficial protein to help reduce the impact of disease or chemotherapy. Genetically engineered proteins can closely resemble the natural proteins they replace, or they can be enhanced by adding sugars or other molecules that extend the protein’s duration of activity.