Biomaterial Database

Significance of catalase in peroxisomal fatty acyl-CoA beta-oxidation. 1987

F Hashimoto, and H Hayashi

Catalase activity was inhibited by aminotriazole administration to rats in order to evaluate the influence of catalase on the peroxisomal fatty acyl-CoA beta-oxidation system. 2 h after the administration of aminotriazole, peroxisomes were prepared from rat liver, and the activities of catalase, the beta-oxidation system and individual enzymes of beta-oxidation (fatty acyl-CoA oxidase, crotonase, beta-hydroxybutyryl-CoA dehydrogenase and thiolase) were determined. Catalase activity was decreased to about 2% of the control. Among the individual enzymes of the beta-oxidation system, thiolase activity was decreased to 67%, but the activities of fatty acyl-CoA oxidase, crotonase and beta-hydroxybutyryl-CoA dehydrogenase were almost unchanged. The activity of the peroxisomal beta-oxidation system was assayed by measuring palmitoyl-CoA-dependent NADH formation, and the activity of the purified peroxisome preparation was found to be almost unaffected by the administration of aminotriazole. The activity of the system in the aminotriazole-treated preparation was, however, significantly decreased to 55% by addition of 0.1 mM H2O2 to the incubation mixture. Hydrogen peroxide (0.1 mM) reduced the thiolase activity of the aminotriazole-treated peroxisomes to approx. 40%, but did not affect the other activities of the system. Thiolase activity of the control preparation was decreased to 70% by addition of hydrogen peroxide (0.1 mM). The half-life of 0.1 mM H2O2 added to the thiolase assay mixture was 2.8 min in the case of aminotriazole-treated peroxisomes, and 4 s in control peroxisomes. The ultraviolet spectrum of acetoacetyl-CoA (substrate of thiolase) was clearly changed by addition of 0.1 mM H2O2 to the thiolase assay mixture without the enzyme preparation; the absorption bands at around 233 nm (possibly due to the thioester bond of acetoacetyl-CoA) and at around 303 nm (due to formation of the enolate ion) were both significantly decreased. These results suggest that H2O2 accumulated in peroxisomes after aminotriazole treatment may modify both thiolase and its substrate, and consequently suppress the fatty acyl-CoA beta-oxidation. Therefore, catalase may protect thiolase and its substrate, 3-ketoacyl-CoA, by removing H2O2, which is abundantly produced during peroxisomal enzyme reactions.

UI	MeSH Term	Description	Entries
D007535	Isomerases	A class of enzymes that catalyze geometric or structural changes within a molecule to form a single product. The reactions do not involve a net change in the concentrations of compounds other than the substrate and the product.(from Dorland, 28th ed) EC 5.	Isomerase
D008297	Male		Males
D008830	Microbodies	Electron-dense cytoplasmic particles bounded by a single membrane, such as PEROXISOMES; GLYOXYSOMES; and glycosomes.	Glycosomes,Glycosome,Microbody
D009097	Multienzyme Complexes	Systems of enzymes which function sequentially by catalyzing consecutive reactions linked by common metabolic intermediates. They may involve simply a transfer of water molecules or hydrogen atoms and may be associated with large supramolecular structures such as MITOCHONDRIA or RIBOSOMES.	Complexes, Multienzyme
D011919	Rats, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations or by parent x offspring matings carried out with certain restrictions. This also includes animals with a long history of closed colony breeding.	August Rats,Inbred Rat Strains,Inbred Strain of Rat,Inbred Strain of Rats,Inbred Strains of Rats,Rat, Inbred Strain,August Rat,Inbred Rat Strain,Inbred Strain Rat,Inbred Strain Rats,Inbred Strains Rat,Inbred Strains Rats,Rat Inbred Strain,Rat Inbred Strains,Rat Strain, Inbred,Rat Strains, Inbred,Rat, August,Rat, Inbred Strains,Rats Inbred Strain,Rats Inbred Strains,Rats, August,Rats, Inbred Strain,Strain Rat, Inbred,Strain Rats, Inbred,Strain, Inbred Rat,Strains, Inbred Rat
D002374	Catalase	An oxidoreductase that catalyzes the conversion of HYDROGEN PEROXIDE to water and oxygen. It is present in many animal cells. A deficiency of this enzyme results in ACATALASIA.	Catalase A,Catalase T,Manganese Catalase,Mn Catalase
D004746	Enoyl-CoA Hydratase	An enzyme that catalyzes reversibly the hydration of unsaturated fatty acyl-CoA to yield beta-hydroxyacyl-CoA. It plays a role in the oxidation of fatty acids and in mitochondrial fatty acid synthesis, has broad specificity, and is most active with crotonyl-CoA. EC 4.2.1.17.	3-Hydroxyacyl CoA Hydrolyases,3-Hydroxyacyl Dehydratases,Crotonase,Enoyl Hydrase,beta-Hydroxyacyl Dehydratases,Enoyl CoA Hydratases,beta-Hydroxyacyl-CoA Dehydrases,trans-2-Enoyl-Coenzyme A Hydratase,3 Hydroxyacyl CoA Hydrolyases,3 Hydroxyacyl Dehydratases,CoA Hydratases, Enoyl,CoA Hydrolyases, 3-Hydroxyacyl,Dehydrases, beta-Hydroxyacyl-CoA,Dehydratases, 3-Hydroxyacyl,Dehydratases, beta-Hydroxyacyl,Enoyl CoA Hydratase,Hydrase, Enoyl,Hydratase, Enoyl-CoA,Hydratase, trans-2-Enoyl-Coenzyme A,Hydratases, Enoyl CoA,Hydrolyases, 3-Hydroxyacyl CoA,beta Hydroxyacyl CoA Dehydrases,beta Hydroxyacyl Dehydratases,trans 2 Enoyl Coenzyme A Hydratase
D006861	Hydrogen Peroxide	A strong oxidizing agent used in aqueous solution as a ripening agent, bleach, and topical anti-infective. It is relatively unstable and solutions deteriorate over time unless stabilized by the addition of acetanilide or similar organic materials.	Hydrogen Peroxide (H2O2),Hydroperoxide,Oxydol,Perhydrol,Superoxol,Peroxide, Hydrogen
D000101	Acetyl-CoA C-Acetyltransferase	An enzyme that catalyzes the formation of acetoacetyl-CoA from two molecules of ACETYL COA. Some enzymes called thiolase or thiolase-I have referred to this activity or to the activity of ACETYL-COA C-ACYLTRANSFERASE.	Acetoacetyl CoA Thiolase,Acetyl Coenzyme A Acetyltransferase,Acetyl-CoA Acetyltransferase,Acetyl CoA Acetyltransferase,Acetyl CoA C Acetyltransferase,Acetyltransferase, Acetyl-CoA,C-Acetyltransferase, Acetyl-CoA,CoA Thiolase, Acetoacetyl,Thiolase, Acetoacetyl CoA
D000102	Acetyl-CoA C-Acyltransferase	Enzyme that catalyzes the final step of fatty acid oxidation in which ACETYL COA is released and the CoA ester of a fatty acid two carbons shorter is formed.	3-Ketoacyl CoA Thiolase,3-Ketothiolase,Acetyl CoA Acyltransferase,Acetyl Coenzyme A Acyltransferase,beta-Ketothiolase,2-Methylacetoacetyl CoA Thiolase,3-Oxoacyl CoA Thiolase,3-Oxoacyl-Coenzyme A Thiolase,beta-Ketoacyl Thiolase,Acetyl CoA C Acyltransferase,Acyltransferase, Acetyl CoA,C-Acyltransferase, Acetyl-CoA,CoA Acyltransferase, Acetyl,CoA Thiolase, 2-Methylacetoacetyl,CoA Thiolase, 3-Ketoacyl,CoA Thiolase, 3-Oxoacyl,Thiolase, 2-Methylacetoacetyl CoA,Thiolase, 3-Ketoacyl CoA,Thiolase, 3-Oxoacyl CoA,Thiolase, 3-Oxoacyl-Coenzyme A,Thiolase, beta-Ketoacyl,beta Ketoacyl Thiolase,beta Ketothiolase