Cathepsin

**Semantic type:** Amino Acid, Peptide, or Protein|Enzyme

**Definition:** Lysosomal proteinases or endopeptidases that function optimally at an acidic pH to catalyze the hydrolysis of peptidic bonds. Elevated cathepsin enzyme activity in either serum or extracellular matrix is often indicative of pathological conditions such as Alzheimer's disease, several types of cancer, arthritis, and osteoporosis.

**Synonyms:** - CATHEPSIN - Cathepsins