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[Peroxisomal beta-oxidation].
Verh K Acad Geneeskd Belg. 1993; 55(1):45-78.VK

Abstract

In animal cells peroxisomes as well as mitochondria are capable of degrading lipids via beta-oxidation. Nevertheless, there are important differences between the two systems. 1) The peroxisomal and mitochondrial beta-oxidation enzymes are different proteins. 2) Peroxisomal beta-oxidation does not degrade fatty acids completely but acts as a chain-shortening system, catalyzing only a limited number of beta-oxidation cycles. 3) Peroxisomal beta-oxidation is not coupled to oxidative phosphorylation and is thus less efficient than mitochondrial beta-oxidation as far as energy conservation is concerned. 4) Peroxisomal beta-oxidation is not regulated by malonyl-CoA and--as a consequence--by feeding as opposed to starvation. Peroxisomes are responsible for the beta-oxidation of very long chain (> C20) fatty acids, dicarboxylic fatty acids, 2-methyl-branched fatty acids, prostaglandins, leukotrienes, and the carboxyl side chains of certain xenobiotics and of the bile acid intermediates di- and trihydroxycoprostanic acids. Mitochondria oxidize mainly long (C16-C20) chain fatty acids, which--because of their abundance--constitute a major source of metabolic fuel. The first step in peroxisomal beta-oxidation is catalyzed by two acyl-CoA oxidases in extrahepatic tissues and by three acyl-CoA oxidases in liver, each enzyme having its own substrate specificity. Palmitoyl-CoA oxidase and pristanoyl-CoA oxidase are found in liver and extrahepatic tissues. The former enzyme oxidizes the CoA esters of straight chain fatty acids, dicarboxylic fatty acids and prostaglandins; the latter enzyme oxidizes the CoA esters of branched fatty acids but also shows some activity towards straight chain and dicarboxylic fatty acids. Hepatic peroxisomes contain a third acyl-CoA oxidase, trihydroxycoprostanoyl-CoAA oxidase, which oxidizes the CoA esters of the bile acid intermediates di- an trihydroxycoprostanic acids. Treatment of rodents with a number of structurally diverse compounds called peroxisome proliferators, results in the proliferation of peroxisomes, especially in liver, and in the induction of the hepatic peroxisomal beta-oxidation enzymes except pristanoyl-CoA oxidase and trihydroxycoprostanoyl-CoA oxidase. There exist several inborn errors, in which peroxisomal beta-oxidation is deficient. These diseases are characterized by severe neurological symptoms. The biochemical findings in these diseases confirm the function of peroxisomal beta-oxidation as described above.

Authors+Show Affiliations

Afdeling Farmacologie, Faculteit Geneeskunde, Katholieke Universiteit Leuven.No affiliation info available

Pub Type(s)

English Abstract
Journal Article
Review

Language

dut

PubMed ID

8480447

Citation

Mannaerts, G P., and P P. Van Veldhoven. "[Peroxisomal Beta-oxidation]." Verhandelingen - Koninklijke Academie Voor Geneeskunde Van Belgie, vol. 55, no. 1, 1993, pp. 45-78.
Mannaerts GP, Van Veldhoven PP. [Peroxisomal beta-oxidation]. Verh K Acad Geneeskd Belg. 1993;55(1):45-78.
Mannaerts, G. P., & Van Veldhoven, P. P. (1993). [Peroxisomal beta-oxidation]. Verhandelingen - Koninklijke Academie Voor Geneeskunde Van Belgie, 55(1), 45-78.
Mannaerts GP, Van Veldhoven PP. [Peroxisomal Beta-oxidation]. Verh K Acad Geneeskd Belg. 1993;55(1):45-78. PubMed PMID: 8480447.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - [Peroxisomal beta-oxidation]. AU - Mannaerts,G P, AU - Van Veldhoven,P P, PY - 1993/1/1/pubmed PY - 1993/1/1/medline PY - 1993/1/1/entrez SP - 45 EP - 78 JF - Verhandelingen - Koninklijke Academie voor Geneeskunde van Belgie JO - Verh K Acad Geneeskd Belg VL - 55 IS - 1 N2 - In animal cells peroxisomes as well as mitochondria are capable of degrading lipids via beta-oxidation. Nevertheless, there are important differences between the two systems. 1) The peroxisomal and mitochondrial beta-oxidation enzymes are different proteins. 2) Peroxisomal beta-oxidation does not degrade fatty acids completely but acts as a chain-shortening system, catalyzing only a limited number of beta-oxidation cycles. 3) Peroxisomal beta-oxidation is not coupled to oxidative phosphorylation and is thus less efficient than mitochondrial beta-oxidation as far as energy conservation is concerned. 4) Peroxisomal beta-oxidation is not regulated by malonyl-CoA and--as a consequence--by feeding as opposed to starvation. Peroxisomes are responsible for the beta-oxidation of very long chain (> C20) fatty acids, dicarboxylic fatty acids, 2-methyl-branched fatty acids, prostaglandins, leukotrienes, and the carboxyl side chains of certain xenobiotics and of the bile acid intermediates di- and trihydroxycoprostanic acids. Mitochondria oxidize mainly long (C16-C20) chain fatty acids, which--because of their abundance--constitute a major source of metabolic fuel. The first step in peroxisomal beta-oxidation is catalyzed by two acyl-CoA oxidases in extrahepatic tissues and by three acyl-CoA oxidases in liver, each enzyme having its own substrate specificity. Palmitoyl-CoA oxidase and pristanoyl-CoA oxidase are found in liver and extrahepatic tissues. The former enzyme oxidizes the CoA esters of straight chain fatty acids, dicarboxylic fatty acids and prostaglandins; the latter enzyme oxidizes the CoA esters of branched fatty acids but also shows some activity towards straight chain and dicarboxylic fatty acids. Hepatic peroxisomes contain a third acyl-CoA oxidase, trihydroxycoprostanoyl-CoAA oxidase, which oxidizes the CoA esters of the bile acid intermediates di- an trihydroxycoprostanic acids. Treatment of rodents with a number of structurally diverse compounds called peroxisome proliferators, results in the proliferation of peroxisomes, especially in liver, and in the induction of the hepatic peroxisomal beta-oxidation enzymes except pristanoyl-CoA oxidase and trihydroxycoprostanoyl-CoA oxidase. There exist several inborn errors, in which peroxisomal beta-oxidation is deficient. These diseases are characterized by severe neurological symptoms. The biochemical findings in these diseases confirm the function of peroxisomal beta-oxidation as described above. SN - 0302-6469 UR - https://www.unboundmedicine.com/medline/citation/8480447/[Peroxisomal_beta_oxidation]_ DB - PRIME DP - Unbound Medicine ER -