Serine peptidase inhibitor, Kunitz type 3 (SPINT3)

Serine peptidase inhibitor, Kunitz type 3 (SPINT3) is a small protein characterized by the presence of a Kunitz-type domain, approximately 50–60 amino acids in length, stabilized by three disulfide bonds. Kunitz-type domains are canonical proteinase inhibitor motifs, acting primarily by binding the active site of serine proteases to block their catalytic activity. Members of the family play central roles in regulating physiological processes such as blood coagulation, tissue inflammation, and the immune response. In some organisms, they protect against microbial pathogens and facilitate collagen synthesis. SPINT3 and related proteins are notable as therapeutic targets and drug scaffolds, especially for disorders involving proteolytic imbalance such as hereditary angioedema. If further granularity (species, isoform, gene) is needed, additional data sources may clarify exact sequence and functional annotation.

Other names

SPINT3Kunitz-type serine protease inhibitor 3Kunitz domain protein 3

Competitive inhibition of the active site of target serine proteases (e.g., trypsin, kallikrein, elastase) and Allosteric modulation in some cases