1.5.5.2 N-propargylglycine irreversibly inactivates PutA by covalently linking the flavin N(5) atom to the epsilon-amino of Lys329. Inactivation locks PutA into a conformation that may mimic the proline-reduced, membrane-associated form 37731 1.5.5.2 pyrrolidone-5-carboxylate - 220824 1.5.5.2 pyruvate - 31 1.5.5.2 rotenone an inhibitor of Complex I, addition of ROT only modestly affects PRODH/POX activity 777 1.5.5.2 succinate uncompetitive inhibitor, in the presence of low levels of proline in vivo, higher levels of succinate can act to inhibit PRODH/POX activity and reactive oxygena species generation. The affinity of succinate is for the enzyme-substrate complex of PRODH/POX and proline rather than for the enzyme binding site for proline. Succinate protects electron transport chain component proteins from PRODH/POX reactive oxygen species-mediated downregulation with almost the same efficacy as 3,4-dehydro-L-proline and N-acetyl-L-cysteine 58 1.5.5.2 thiazolidine-2-carboxylate a mechanism-based inactivator of PRODH. PRODH catalyzes the oxidation of thiazolidine-2-carboxylate at the C atom adjacent to the S atom of the thiazolidine ring (C5). Then, the N5 atom of the reduced FAD attacks the C5 of the oxidized T2C species, resulting in a covalent adduct 45933