Matrix degrading enzymes are implicated in several disease processes such as abdominal aortic aneurysms and emphysema, however, monitoring proteolytic activity in a single assay is not well-established. Numerous assays have been developed to measure matrix degrading enzymes, which use artificial substrates or substrates derived from natural substrate protein. We have recently developed an assay for elastolytic activity based on the detection of primary amines, using trinitrobenzene sulfonic acid (TNBSA), following the digestion of succinylated elastin. The assay is also versatile enough to allow the detection of other proteases through the use of succinylated substrate specific for given protease.