Peroxisomes are ubiquitous organelles in eukaryotes that function to rid the cell of toxic substances. They have a single membrane that separates their contents from the cytosol (the internal fluid of the cell) and that contains membrane proteins critical for various functions, such as importing proteins into the organelles and aiding in proliferation. Unlike lysosomes, which are formed in the secretory pathway, peroxisomes usually self-replicate by enlarging and then dividing, although there is some indication that new ones may be formed directly. Peroxisomes were discovered by the Belgian cytologist Christian de Duve in 1965.

PMP70

• a Peroxisome Membrane Protein. PMID: 12232329

Catalase

• localized to the structures containing a 70-kDa peroxisomal membrane protein. In 65TS, catalase-less peroxisomes are the direct precursors of peroxisomes. PMID: 10960480
• catalase was demonstrable exclusively in the matrix of all peroxisomes in hepatic parenchymal cells of normal and peroxisome proliferator-treated rats. PMID: 7120922

Carnitine Acetyltransferase (CAT)

• Carnitine acetyltransferase (CAT; EC 2.3.1.7) is localized in two subcellular organelles, peroxisomes and mitochondria, in an n-alkane-assimilating yeast, Candida tropicalis. PMID: 9565689, PMID: 8947834
• Localized in mitochondria of rat myocardium. PMID: 8142416
• present in peroxisomes, mitochondria, and cytosol. PMID: 8405946
• discovered in mitochondria and microbodies of cardiomyocytes, hepatocytes and fibers of the skeletal muscle of intact rats. PMID: 6871452