Thioarginine is a colorimetric substrate for arginase.
1 Arginase binds to and hydrolyzes thioarginine to release 2-amino-5-mercaptovaleric acid, which reacts with DTNB (Ellman's reagent) to form 2-nitro-5-thiobenzoate and can be quantified by colorimetric detection at 412 nm as a measure of arginase activity.
