L-Propargylglycine methyl ester hydrochloride is primarily utilized in biochemical research as an inhibitor of enzymes involved in amino acid metabolism. It is particularly effective in studying the function of enzymes like cystathionine gamma-lyase (CSE) and cystathionine beta-synthase (CBS), which play crucial roles in the transsulfuration pathway. By inhibiting these enzymes, researchers can investigate the physiological and pathological roles of hydrogen sulfide (H₂S) and other sulfur-containing compounds in various biological processes, including inflammation, cardiovascular function, and neuroprotection. Additionally, this compound is used in the synthesis of analogs and derivatives for further pharmacological studies, aiding in the development of potential therapeutic agents targeting related metabolic pathways.