Enzyme inhibitor
This potent PLA inhibitor (FW = 428.65 g/mol; CAS 221632-26-4; Soluble to 10 mM in DMSO with gentle warming), also named 4-(4- octadecylphenyl)-4-oxobutenoic acid, targets phospholipase A2 (IC50 = 70 nM). OBAA is a mechanism-based inhibitor, showing a typical timedependence as well as a molar inactivation ratio of twenty OBAA hydrolyzed per molecule of irreversibly inactivated enzyme. Doublereciprocal replots of the apparent inactivation constants versus OBAA concentration gave a (pseudo) first-order rate constant of inactivation of 2.3 min–1 and a dissociation constant of 6 x 10–6 M–1 for the enzyme-inhibitor intermediate. OBAA reduces bronchospasm in guinea pigs in vivo.
