Prenylcysteine oxidase that cleaves the thioether bond of prenyl-L-cysteines, such as farnesylcysteine and geranylgeranylcysteine (PubMed:12151402). Only active against free prenylcysteines and not prenylcysteine residues within prenylated proteins or peptides (By similarity). Involved in the final step in the degradation of prenylated proteins, by degrading prenylcysteines after the protein has been degraded (PubMed:12151402). an S-prenyl-L-cysteine + H2O + O2 = a prenal + H2O2 + L-cysteine H2O + O2 + S-(2E,6E)-farnesyl-L-cysteine = (2E,6E)-farnesal + H2O2 + L-cysteine [(2E,6E,10E)-geranylgeranyl]-L-cysteine + H2O + O2 = (2E,6E,10E)-geranylgeranial + H2O2 + L-cysteine Highly expressed in the liver, kidney, heart and brain. Mice are healthy and fertile, but show an accumulation of prenylcysteines within cells (PubMed:12151402). Significant accumulation of both farnesylcysteine and geranylgeranylcysteine in the brain and liver (PubMed:12151402). Belongs to the prenylcysteine oxidase family.