Human neutrophil elastase functions as a type III collagen 'collagenase'
Under physiologic conditions, human neutrophil elastase cleaves triple helical human type III collagen into specific fragments in a fashion similar to that of a typical 'collagenase'. In contrast, elastase does not attack the triple helical portion of type I collagen. However, unlike a classic collagenase, which is a metalloenzyme, the action of elastase on type III collagen is prevented by serine protease inhibitors. These findings suggest that the concepts of 'collagenases' and 'elastases' must be broadened and that human neutrophil elastase is capable of mediating a broad range of connective tissue destruction.