Serine Protease

Serine proteases are a large family of proteolytic enzymes that use an active-site serine residue to cleave protein substrates and thereby regulate diverse biological functions through controlled proteolysis^[1]. Mechanistically, these enzymes participate in fundamental pathways including blood coagulation, apoptosis, inflammation, immune defense, and tissue remodeling, making proteolytic regulation a central component of cellular and physiological homeostasis^[1]. Because excessive or uncontrolled protease activity can damage host tissues, serine protease activity is tightly regulated by endogenous inhibitors, particularly serpins, which help maintain balanced proteolytic signaling networks^[1][2]. In disease contexts, dysregulation of serine proteases or their inhibitors has been associated with immune-mediated disorders, inflammatory pathology, cardiovascular disease, cancer, and neurological disorders, highlighting their importance as mechanistic drivers and biomarkers of disease processes^[1][2]. Compared with related protease classes, serine proteases are distinguished by their catalytic serine-dependent mechanism and represent one of the largest protease families identified in humans, encompassing multiple subfamilies with distinct substrate specificities, including trypsin-like, chymotrypsin-like, and elastase-like enzymes^[1]. For experimental applications, selective serine protease inhibitors are widely used to investigate proteolytic pathways, define enzyme-specific biological functions, and support the development of therapeutic strategies targeting pathological protease activity^[2][3].