Phytanic alpha-oxidation

D-bifunctional protein deficiency [5], 2-methyl acyl-CoA racemase (AMACR) deficiency [3] and sterol carrier protein (SCP-x) deficiency [6], the disorders of etherphospholipid biosynthesis (dihydroxyacetone phosphate acyltransferase and alkyl- dihydroxyacetone phosphate synthase deficiency) [2], the disorders of phytanic acid alpha-oxidation (Refsum disease) [15], and the disorders of glyoxylate detoxification with hyperoxaluria type 1 as caused by alanine glyoxylate aminotransferase deficiency as a sole representative. 

Eldjarn L, Stokke O, Try K. 1966. Alpha-oxidation of branched chain fatty acids in man and its failure in patients with Refsum s disease showing phytanic acid accumulation. Scand J Clin Lab Invest 18 694-695. 

Watkins, P.A., Howard, A.E. Mihalil S.J. (1994) Biochim. Biophys. Acta 1214, 288-294. Phytanic acid must be activated to phytanoyl-CoA prior to its alpha-oxidation in rat liver peroxisomes. 

Mihalik, S.J., Rainville, A.M. Watkins, P.A. ( 995)Eur. J. Biochem. 232, 545-551. Phytanic acid alpha-oxidation in rat liver peroxisomes. Production of alpha-hydroxyphytanoyl-CoA and formate is enhanced by dioxygenase cofactors. 

Jansen, G.A., Mihalik, SJ., Watkins, P.A., Moser, H.W., Jakobs, C, Denis, S. Wanders, R.J.A. (19%) Biochem. Biophys. Res. Commun. 229, 205-210. Phytanoyl-CoA hydroxylase is present in human liver, located in peroxisomes, and deficient in Zellweger syndrome direct, unequivocal evidence for the new, revised pathway of phytanic acid alpha-oxidation in humans. 

Tsai, S.C., Avigan, J. Steinberg, D. (1969) J. Biol. Chem. 244, 2682-2692. Studies on the alpha oxidation of phytanic acid hy rat liver mitochondria. 

Singh, 1., Pahan, K., Dhaunsi, G.S., Lazo, O. Ozand, P. (1993) J. Biol. Chem. 268, 9972-9979. Phytanic acid alpha-oxidation. Differential suhcellular localization in rat and human tissues and its inhibition by nycodenz. 

Wanders, R.J. van Roermund, C.W. (1993) Biochim. Biophys. Acta 1167, 345-350. Studies on phytanic acid alpha-oxidation in rat liver and cultured human skin fibroblasts. 

The commonest polymethyl-branched fatty acid is probably phytanic or 3,7,11,15-tetramethylhexa-decanoic acid, which is a metabolite of phytol, and can be found in trace amounts in many animal tissues. It becomes a major component of the plasma lipids in Refsum s syndrome, a rare condition in which there is a deficiency in the enzymatic fatty acid alpha-oxidation system. Lough [562] has reviewed the occurrence and biochemistry of this and other isoprenoid fatty acids. Similar fatty acids are present in the lipids of the preen gland of birds and in those of tubercle bacilli. 

Verhoeven, N.M., Schor, D.S., ten Brink, H.J., Wanders, R.J.A. Jakobs, C. (1997) Biochem. Biophys. Res. Commun. 237, 33-36. Resolution of the phytanic add alpha-oxidation pathway identification of pristanal as product of the decarboxylation of 2-hydroxyphytanoyl-CoA. 

Wanders, R.J.A., Jansen, G.A., and Lloyd, M.D. (2003) Phytanic acid alpha-oxidation, new insights into an old problem a review. Biochim. BiophysActa, 1631, 119-135. 

It is not certain whether phytol is transformed to phytanic acid via the alpha-beta-unsaturated (phytenic) acid, or wether phytanic acid is formed by hydration of phytol to dihydrophytol and consecutive oxidation. The latter possibility seems to be more likely. While a small amount of phytenic acid was found in beta-... 

---