L-Propargylglycine ((S)-Propargylglycine) is an inhibitor of the enzyme.

l-propargylglycine (LPG) irreversibly inhibited the enzyme from Crotalus adamanteus and Crotalus atrox in a dose- and time-dependent manner.?Inactivation was irreversible which was significantly protected by the substrate l-phenylalanine.?A Kitz-Wilson replot of the inhibition kinetics suggested formation of reversible enzyme-LPG complex, which occurred prior to modification and inactivation of the enzyme.?UV-visible and fluorescence spectra of the enzyme and the cofactor strongly suggested formation of covalent adduct between LPG and an active site residue of the enzyme.?A molecular modeling study revealed that the FAD-binding, substrate-binding and the helical domains are conserved in SV-LAAOs and both His223 and Arg322 are the important active site residues that are likely to get modified by LPG.