nor-NOHA (acetate)

L-Arginine serves as a common substrate for both nitric oxide synthase (NOS) and arginase in the cell. NOS catalyzes the oxidation of arginine to citrulline and NO with N^ω-hydroxy-L-arginine (NOHA) formed as an intermediate. Arginase, on the other hand, catalyzes the hydrolysis of arginine into urea and L-ornithine. nor-NOHA (acetate) is a potent, reversible inhibitor of rat liver arginase with a K_i value of 0.5 µM, which is 20-fold lower than the K_i of 10 µM observed for NOHA.¹ It is about 40-fold more potent than NOHA as an inhibitor of arginase from mouse macrophages, exhibiting an IC₅₀ of 10-12 µM.² nor-NOHA (acetate) is not a substrate for any of the 3 NOS isoforms and does not inhibit nNOS or iNOS.^3,4

WARNING This product is not for human or veterinary use.

1. Custot, J., Moali, C., Brollo, M., et al. A new α-amino acid Nw-hydroxy-nor-L-arginine: A highly-affinity inhibitor of arginase well adapted to bind to its manganese cluster. J. Am. Chem. Soc. 119(17), 4086-4087 (1997).

2. Tenu, J.P., Lepoivre, M., Moali, C., et al. Effects of the new arginase inhibitor Nw-hydroxy-nor-L-arginine on NO synthase activity in murine macrophages. Nitric Oxide 3(6), 427-438 (1999).

3. Dijols, S., Perollier, C., Lefevre-Groboillot, D., et al. Oxidation of Nw-hydroxyarginine analogues by NO-synthase: The simple, non amino acid N-butyl N'-hydroxyguanidine is almost as efficient an NO precursor as Nw-hydroxyarginine. J. Med. Chem. 44(20), 3199-3202 (2001).