Proteinase Inhibitor Gene

**Semantic type:** Gene or Genome

**Definition:** Proteinase Inhibitor Genes encode Proteinase Inhibitor Proteins that block the activity of proteases, endopeptidases that catalyze the cleavage of internal peptide bonds in a polypeptide or protein substrate (Serine Endopeptidases, Cysteine Endopeptidases, Aspartic Endopeptidases, Metalloendopeptidases, and other Endopeptidases). (NCI)