Arachidonoyl p-nitroaniline (ApNA) is one of several nitroaniline fatty acid amides which can be used to measure fatty acid amide hydrolase (FAAH) activity. FAAH is a relatively unselective enzyme in that it accepts a variety of amide head groups other than the ethanolamine of its nominal endogenous substrate anandamide (AEA; ). It also will hydrolyze fatty acid amides with fewer carbons and fewer double bonds than arachidonate. (See also Decanoyl p-Nitroaniline - Catalog No. 90349). Exposure of ApNA to FAAH activity results in the release of the yellow colorimetric dye p-nitroaniline (ε = 13,500 at 382 nm). This offers the potential for fast and convenient measurements of FAAH activity using a 96-well plate spectrophotometer.
