Acetaminophen-Cysteine Protein Adduct

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

**Definition:** A modified protein, usually glutathione, where oxidized acetaminophen is bound to the sulfhydryl group of cysteine residues. The presence of acetaminophen-cysteine or its proteolyzed product 3-para cysteinyl acetaminophen in a sample is a specific biomarker for acetaminophen exposure and increased concentrations of these adducts may be associated with acetaminophen toxicity.

**Synonyms:** - APAP-CYS - Acetaminophen Protein Adduct - Acetaminophen-Cysteine - PPA - Paracetamol Protein Adduct - Paracetamol-Cysteine