Unnatural amino acids are specially engineered molecules that expand beyond the twenty naturally occurring amino acids used by living organisms to build proteins. By introducing these synthetic building blocks into proteins, scientists can create entirely new biological functions and properties that are not found in nature.

Proteins are responsible for countless biological processes, including cell signaling, immune responses, and metabolic functions. Traditional proteins are limited by the characteristics of natural amino acids. Unnatural amino acids overcome these limitations by introducing unique chemical groups that can enhance stability, improve targeting capabilities, and increase therapeutic effectiveness.