L-α-(Aminooxy)-β-phenylpropionic acid is primarily used in biochemical research as a selective inhibitor of pyridoxal phosphate-dependent enzymes. It plays a significant role in studying enzyme mechanisms, particularly those involving amino acid metabolism. The compound is also utilized in the development of enzyme inhibitors for therapeutic purposes, targeting specific pathways in diseases where enzyme regulation is critical. Additionally, it serves as a tool in organic synthesis for the preparation of modified amino acids and peptides, aiding in the exploration of structure-activity relationships in drug design.