elastases

Elastases are a group of proteolytic enzymes that hydrolyze elastin, a highly elastic protein that forms a major component of connective tissue in skin, blood vessels, and lungs. They are serine proteases belonging to the chymotrypsin superfamily and typically act on peptide bonds adjacent to hydrophobic residues. Beyond elastin, elastases can cleave a range of extracellular matrix and inflammatory proteins, contributing to tissue remodeling and defense.

In humans, two principal sources are neutrophils and the pancreas. Neutrophil elastase is released from neutrophil azurophilic granules during inflammation and participates in pathogen killing as well as tissue damage if unchecked. Pancreatic elastases are secreted by pancreatic acinar cells into the digestive tract and play a role in digestion; their activity is often assessed clinically through fecal elastase testing to evaluate exocrine pancreatic function. Additional elastases exist in different tissues, including elastases produced by the skin and certain inflammatory cells.

Elastases function within a tightly regulated proteolytic network. They are produced as inactive precursors (zymogens) and activated through proteolytic processing. Their activity is controlled by endogenous inhibitors such as alpha-1 antitrypsin and secretory leukocyte protease inhibitor, among others. Disruption of this balance can cause or exacerbate disease: excess elastase activity can degrade elastin and other matrix components, contributing to emphysema and COPD in smokers or individuals with deficient inhibition; insufficient elastase activity can impair normal tissue remodeling and digestion.

Bacterial elastases, such as those produced by Pseudomonas aeruginosa, act as virulence factors that degrade host proteins and help pathogens evade immune responses.