- Elastase is a serine protease that hydrolyzes peptide bonds, specifically targeting and degrading elastin, a key structural protein that imparts elasticity to tissues such as the lungs, skin, arteries, and ligaments. Elastase exhibits a preference for cleaving peptide bonds after small, neutral amino acids like alanine, glycine, and valine, which are abundant in elastin. This enzyme is critical for the remodeling of extracellular matrix (ECM) components during development, wound healing, and immune responses.
- Several types of elastases exist in mammals, the most well-known being pancreatic elastase, produced as the inactive zymogen proelastase and activated in the small intestine by trypsin, and neutrophil elastase, stored in azurophilic granules of neutrophils and released during inflammation. While pancreatic elastase functions in digestion, neutrophil elastase plays a key role in host defense by degrading bacterial proteins and damaged tissue components at sites of infection or injury.
- Neutrophil elastase is tightly regulated under normal physiological conditions. However, excessive or unregulated elastase activity can lead to tissue destruction and is implicated in the pathogenesis of several inflammatory and degenerative diseases. For example, in chronic obstructive pulmonary disease (COPD) and emphysema, overactive neutrophil elastase degrades lung tissue, particularly alveolar walls rich in elastin. To prevent such damage, the body produces endogenous inhibitors like α1-antitrypsin, which neutralizes elastase. Genetic deficiency of α1-antitrypsin leads to increased elastase activity and predisposition to early-onset emphysema.
- In research and clinical diagnostics, elastase serves as a marker for pancreatic function. Fecal elastase levels are used to assess exocrine pancreatic insufficiency, especially in conditions such as chronic pancreatitis or cystic fibrosis. Recombinant elastase is also used in laboratory settings to selectively digest ECM proteins or to study protease function.
- In summary, elastase is a versatile serine protease with distinct roles in digestion, immunity, and tissue remodeling. While essential for normal physiology, its activity must be tightly regulated to prevent proteolytic tissue injury and inflammation-related diseases.
