Peroxisome

Basic structure of a peroxisome
Distribution of peroxisomes (white) in HEK 293 cells during mitosis
Peroxisome in rat neonatal cardiomyocyte staining The SelectFX Alexa Fluor 488 Peroxisome Labeling Kit directed against peroxisomal membrane protein 70 (PMP 70)
Peroxisome in rat neonatal cardiomyocyte

A peroxisome (IPA: [pɛɜˈɹɒksɪˌsoʊm]) [1] is a membrane-bound organelle, a type of microbody, found in the cytoplasm of virtually all eukaryotic cells.[2][3] Peroxisomes are oxidative organelles. Frequently, molecular oxygen serves as a co-substrate, from which hydrogen peroxide (H2O2) is then formed. Peroxisomes owe their name to hydrogen peroxide generating and scavenging activities. They perform key roles in lipid metabolism and the reduction of reactive oxygen species.[4]

Peroxisomes are involved in the catabolism of very long chain fatty acids, branched chain fatty acids, bile acid intermediates (in the liver), D-amino acids, and polyamines. Peroxisomes also play a role in the biosynthesis of plasmalogens: ether phospholipids critical for the normal function of mammalian brains and lungs.[5] Peroxisomes contain approximately 10% of the total activity of two enzymes (Glucose-6-phosphate dehydrogenase and 6-Phosphogluconate dehydrogenase) in the pentose phosphate pathway,[6] which is important for energy metabolism.[5] It is vigorously debated whether peroxisomes are involved in isoprenoid and cholesterol synthesis in animals.[5] Other peroxisomal functions include the glyoxylate cycle in germinating seeds ("glyoxysomes"), photorespiration in leaves,[7] glycolysis in trypanosomes ("glycosomes"), and methanol and amine oxidation and assimilation in some yeasts.

  1. ^ "Definition of PEROXISOME". www.merriam-webster.com. Retrieved 2019-10-30.
  2. ^ Islinger M, Voelkl A, Fahimi HD, Schrader M (November 2018). "The peroxisome: an update on mysteries 2.0". Histochemistry and Cell Biology. 150 (5): 443–471. doi:10.1007/s00418-018-1722-5. PMC 6182659. PMID 30219925.
  3. ^ O'Connell JD, Zhao A, Ellington AD, Marcotte EM (2012). "Dynamic reorganization of metabolic enzymes into intracellular bodies". Annu Rev Cell Dev Biol. 28: 89–111. doi:10.1146/annurev-cellbio-101011-155841. PMC 4089986. PMID 23057741.
  4. ^ Bonekamp NA, Völkl A, Fahimi HD, Schrader M (2009). "Reactive oxygen species and peroxisomes: struggling for balance". BioFactors. 35 (4): 346–55. doi:10.1002/biof.48. PMID 19459143. S2CID 7502822.
  5. ^ a b c Wanders RJ, Waterham HR (2006). "Biochemistry of mammalian peroxisomes revisited". Annual Review of Biochemistry. 75: 295–332. doi:10.1146/annurev.biochem.74.082803.133329. PMID 16756494.
  6. ^ Antonenkov, Vasily D. (Jul 1989). "Dehydrogenases of the pentose phosphate pathway in rat liver peroxisomes". European Journal of Biochemistry. 183 (1): 75–82. doi:10.1111/j.1432-1033.1989.tb14898.x. ISSN 0014-2956. PMID 2753047.
  7. ^ Evert RF, Eichhorn SE (2006). Esau's Plant Anatomy: Meristems, Cells, and Tissues of the Plant Body: Their Structure, Function, and Development. John Wiley & Sons. ISBN 9780471738435.