p-Ethynylphenylalanine（Cat No.:I015571）is a noncanonical amino acid featuring an ethynyl group substituted at the para-position of the phenyl ring. This functional handle allows bioorthogonal chemistry, particularly click reactions, enabling site-specific protein labeling, conjugation, and structural studies. It can be incorporated into proteins through genetic code expansion or chemical modification, providing a versatile tool for probing protein dynamics, interactions, and localization. Widely used in chemical biology, bioconjugation, and proteomics research, p-ethynylphenylalanine expands the functional diversity of proteins for mechanistic studies and therapeutic development.