Cysteine Proteinase

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

**Definition:** An enzyme that contains an unpaired cysteine in the active site which acts as a nucleophilic thiol to catalyze the proteolytic processing of other proteins or polypeptides.

**Synonyms:** - Cysteine Endopeptidase - Cysteine Peptidase - Cysteine Protease - Thiol Protease