Leukotriene A4 (LTA4) hydrolase/aminopeptidase is a bifunctional zinc metalloenzyme that both catalyzes the synthesis of LTB4 from LTA4 and cleaves the chemotactic peptide Pro-Gly-Pro. ARM1 is a thiazolamine that inhibits LTB4 synthesis in human neutrophils (IC50 = ~0.5 μM) and conversion of LTA4 to LTB4 by purified LTA4 hydrolase (Ki = 2.3 μM). ARM1 does not significantly affect the hydrolysis of Pro-Gly-Pro by LTA4 hydrolase.
