Elastase, like trypsin and chymotrypsin, is a serine protease that also hydrolyses amides and esters. It is produced in the pancreas as an inactive zymogen, proelastase, and activated in the duodenum by trypsin. Elastase is distinctive in that it acts upon elastin.This enzyme degrades elastin, collagen, and proteoglycan and has been implicated in the development of pulmonary emphesema and rheumatoid arthritis.