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Phytanic acid a-oxidation

Wanders, R.J.A. van Roermund, C.W. (1993) Biochim. Biophys. Acta 11S7, 345-350. Studies on phytanic acid a-oxidation in rat liver and cultured human skin fibroblasts. [Pg.279]

Muralidharan, V.B. Kishimoto, Y. (1984)/ Biol Chem. 259, 13021-13026. Phytanic acid a-oxidation in rat liver Requirement for a cytosolic factor. [Pg.279]

Fingerhut, R., Schmitz, W. Conzelmann, E. (1993)/. Inker. Metab. Dis. 16, 591-594. Accumulation of phytanic acid a-oxidation intermediates in Zellweger fibroblasts. [Pg.279]

Singh, I., Pahan, K., Dhaunsi, G.S., Lazo, 0. Ozand, P. (1993) J. Biol. Chem. 26S, 9972-9979. Phytanic acid a-oxidation. Differential subcellular localization in rat and human tissues and its inhibition... [Pg.280]

Mihalik, S.J., Rainville, A.M. Watkins, PA. (1995) Em J. Biochem. 232, 545-551. Phytanic acid a-oxidation in rat liver peroxisomes. Production of a-hydroxyphytanoyl-CoA and formate is enhanced by dioxygenase cofactors. [Pg.280]

Jansen, G.A., Mihalik, SJ., Watkins, PA, Moser, H.W., Jakobs, C., Denis, S. Wanders, R.JA. (19%) Biochem. Biophys. Res. Commun. 229, 205-210. Phytanoyl-CoA hydroxylase is present in human fiver, located in peroxisomes, and deficient in Zellweger syndrome direcl, unequivocal evidence for the new, revised pathway of phytanic acid a-oxidation in humans. [Pg.280]

Verhoeven, N.M., Schor, D.S.M., Previs, S.F., Brunengraber, H. Jakobs, C. (1997) Eur. J. Pediatr. 156, S83-S87. Stable isotope studies of phytanic acid a-oxidation in vivo production of formic acid. [Pg.282]

Recent studies have led to a full resolution of the structure of the phytanic acid a-oxidation pathway. Indeed independent studies by Croes et aC and Verhoeven revealed that 2-hydrox5 hytanoyl-CoA undergoes cleavage to produce formyl-CoA and pristanal respectively, which is than oxidized to pristanic acid (Fig. 3B). The pristanic acid is now ready for p-oxidation after its activation to its CoA-ester. [Pg.293]

Figures 25.3 and 25.4 depict the enzymology of the etherphospholipid biosynthesis and phytanic acid a-oxidation systems, respectively (see legends for detailed information). Figures 25.3 and 25.4 depict the enzymology of the etherphospholipid biosynthesis and phytanic acid a-oxidation systems, respectively (see legends for detailed information).
The finding that there is accumulation of phytanic acid (3,7,11,15-tetramethyl-hexadecanoic acid) in plasma from Zellweger patients, suggested that peroxisomes might also play a major role in phytanic acid a-oxidation. The pathway of phytanic acid a-oxidation was unknown, however, and the role of peroxisomes disputed. Studies from different laboratories including our own have now led to a full resolution of the pathway... [Pg.284]

Figure 3B. New. revised phytanic acid a-oxidation pathway. See text for detailed information. Figure 3B. New. revised phytanic acid a-oxidation pathway. See text for detailed information.
Figure 4 Peroxisomal fatty-acid (FA) /3-oxidation pathways. While saturated long-chain fatty acids (LCFA) are preferentially degrade in mitochondria, saturated very-long-chain fatty acids (VLCFA) and some LCFA are shortened by peroxisomal /3-oxidation. Degradation of pristanic acid, the product of phytanic acid a-oxidation, and the conversion of the cholesterol-derived 27-carbon bile-acid precursors dihydroxycholestanoic acid (DHCA) and trihydroxycholestanoic acid (THCA) to 24-carbon bile acids also require this pathway. The mechanism by which these substrates enter peroxisomes is unknown. Four enzymatic reactions serve to shorten the substrates by either two (LCFA, VLCFA) or three (pristanic acid, DHCA, THCA) carbon atoms. The 2-methyl group of the latter substrates is shown in brackets. SCPx thiolase refers to the thiolase activity of sterol carrier protein x. Figure 4 Peroxisomal fatty-acid (FA) /3-oxidation pathways. While saturated long-chain fatty acids (LCFA) are preferentially degrade in mitochondria, saturated very-long-chain fatty acids (VLCFA) and some LCFA are shortened by peroxisomal /3-oxidation. Degradation of pristanic acid, the product of phytanic acid a-oxidation, and the conversion of the cholesterol-derived 27-carbon bile-acid precursors dihydroxycholestanoic acid (DHCA) and trihydroxycholestanoic acid (THCA) to 24-carbon bile acids also require this pathway. The mechanism by which these substrates enter peroxisomes is unknown. Four enzymatic reactions serve to shorten the substrates by either two (LCFA, VLCFA) or three (pristanic acid, DHCA, THCA) carbon atoms. The 2-methyl group of the latter substrates is shown in brackets. SCPx thiolase refers to the thiolase activity of sterol carrier protein x.
Figure 5 Peroxisomal phytanic acid a-oxidation pathway. The dietary 3-methyl-branched fatty acid phytanic acid is toxic if allowed to accumulate in the tissues. Its 3-methyl group prevents degradation by /3-oxidation therefore, this fatty acid is first shortened by one carbon atom. Like the substrates for peroxisomal /3-oxidation, phytanic acid enters peroxisomes by an unknown mechanism. Activated phytanic acid is hydroxylated on carbon 2. Cleavage between carbons 1 and 2 yields a one-carbon CoA compound, formyl-CoA, and an aldehyde, pristanal. After oxidation and reactivation to the CoA derivative, pristanoyl-CoA can be degraded by /3-oxidation. Figure 5 Peroxisomal phytanic acid a-oxidation pathway. The dietary 3-methyl-branched fatty acid phytanic acid is toxic if allowed to accumulate in the tissues. Its 3-methyl group prevents degradation by /3-oxidation therefore, this fatty acid is first shortened by one carbon atom. Like the substrates for peroxisomal /3-oxidation, phytanic acid enters peroxisomes by an unknown mechanism. Activated phytanic acid is hydroxylated on carbon 2. Cleavage between carbons 1 and 2 yields a one-carbon CoA compound, formyl-CoA, and an aldehyde, pristanal. After oxidation and reactivation to the CoA derivative, pristanoyl-CoA can be degraded by /3-oxidation.
See other pages where Phytanic acid a-oxidation is mentioned: [Pg.279]    [Pg.279]    [Pg.284]    [Pg.293]    [Pg.485]    [Pg.486]    [Pg.492]    [Pg.503]    [Pg.293]   
See also in sourсe #XX -- [ Pg.273 , Pg.274 , Pg.275 , Pg.276 , Pg.277 , Pg.278 , Pg.279 , Pg.280 , Pg.292 , Pg.293 , Pg.294 , Pg.295 , Pg.296 , Pg.297 , Pg.298 ]

See also in sourсe #XX -- [ Pg.273 , Pg.274 , Pg.275 , Pg.276 , Pg.277 , Pg.278 , Pg.279 , Pg.280 , Pg.292 , Pg.293 , Pg.294 , Pg.295 , Pg.296 , Pg.297 , Pg.298 ]



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In a-oxidation of phytanic acid

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Phytanes

Phytanic

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