Fatty acid methyl-branched

Oxidation is used to break down methyl-branched fatty acids. It takes place through step-by-step removal of Ci residues, begins with a hydroxylation, does not require coenzyme A, and does not produce any ATP. 

Bagneres, A. G Trabalon, M., Blomquist, G. J. and Schulz, S. (1997). Waxes of the social spider Anelosimus eximus abundance of novel -propyl esters of long-chain methyl-branched fatty acids. Archives of Insect Biochemistry and Physiology 36 295-314. 

Juarez, P., Chase, J. and Blomquist, G. J. (1992). A microsomal fatty acid synthetase from the integument of Blattella germanica synthesizes methyl-branched fatty acids, precursors to hydrocarbon and contact sex pheromone. Archives of Biochemistry and Biophysics 293 333-341. 

A microsomal FAS was implicated in the biosynthesis of methyl-branched fatty acids and methyl-branched hydrocarbon precursors of the German cockroach contact sex pheromone (Juarez et al., 1992 Gu et al., 1993). A microsomal FAS present in the epidermal tissues of the housefly is responsible for methyl-branched fatty acid production (Blomquist et al., 1994). The housefly microsomal and soluble FASs were purified to homogeneity (Gu et al., 1997) and the microsomal FAS was shown to preferentially use methylmalonyl-CoA in comparison to the soluble FAS. GC-MS analyses showed that the methyl-branching positions of the methyl-branched fatty acids of the housefly were in positions consistent with their role as precursors of the methyl-branched hydrocarbons. 

The methylmalonyl-CoA unit, which is the precursor to methyl-branched fatty acids and hydrocarbons, arises from the carbon skeletons of valine and isoleucine, but not succinate (Dillwith et al., 1982). Propionate is also a precursor to methylmalonyl-CoA, and in the course of these studies, a novel pathway for... 

Blomquist G. J., Guo L., Gu P., Blomquist C., Reitz R. C. and Reed J. R. (1994) Methyl-branched fatty acids and their biosynthesis in the housefly, Musca domestica L. (Diptera Muscidae). Insect Biochem. Mol. Biol. 24, 803-810. 

Gu P, Welch W. H. and Blomquist G. J. (1993) Methyl-branched fatty acid biosynthesis in the German cockroach, Blattella germanica kinetic studies comparing a microsomal and soluble fatty acid synthetases. Insect Biochem. Mol. Biol. 23, 263-271. 

Methyl-branched fatty acids are intermediates in branched alkane biosynthesis (Juarez et al., 1992). Thus, [l-14C]propionate labeled methyl-branched fatty acids of 16-20 carbons, but did not label straight chain-saturated and monounsaturated fatty acids (Chase et al., 1990). 

Methyl-branched fatty acids and their biosynthesis in the housefly, Musca domestica L. (Diptera Muscidae). Insect Biochem. Mol. Biol., 24, 803-810. 

Fatty acids with trans or non-methylene-interrupted unsaturation occur naturally or are formed during processing for example, vaccenic acid (18 1 Hr) and the conjugated linoleic acid (CLA) rumenic acid (18 2 9tllc) are found in dairy fats. Hydroxy, epoxy, cyclopropane, cyclopropene acetylenic, and methyl branched fatty acids are known, but only ricinoleic acid (12(/f)-hydroxy-9Z-octadecenoic acid) (2) from castor oil is used for oleochemical production. OUs containing vernolic acid (12(5),13(/ )-epoxy-9Z-octadecenoic acid) (3) have potential for industrial use. 

Although the mitochondria are the primary site of oxidation for dietary and storage fats, the peroxisomal oxidation pathway is responsible for the oxidation of very long-chain fatty acids, jS-methyl branched fatty acids, and bile acid precursors. The peroxisomal pathway also plays a role in the oxidation of dicarboxylic acids. In addition, it plays a role in isoprenoid biosynthesis and amino acid metabolism. Peroxisomes are also involved in bile acid biosynthesis, a part of plasmalogen synthesis and glyoxylate transamination. Furthermore, the literature indicates that peroxisomes participate in cholesterol biosynthesis, hydrogen peroxide-based cellular respiration, purine, fatty acid, long-chain... 

Baes, M., Huyghe, S., Carmeliet, P., Declercq, P. E., Collen, D., Mannaerts, G. P., and Van Veldhoven, P. P. Inactivation of the peroxisomal multifunctional protein-2 in mice impedes the degradation of not only 2-methyl-branched fatty acids and bile acid intermediates but also of very long chain fatty acids. J Biol Chem 275 (2000) 16329-16336. 

Methyl-branched fatty acids are found in lipid fractions of many plants and are very common in bacterial extracts. Sixteen branched fatty acids were produced by different synthetic methods, including alkylation and hydrolysis of oxazolines to obtain 2-alkyl fatty acids. This was achieved through desulfurization of alkyl-substituted thiophenecarboxylic acids for 4- and 6-alkyl fatty acids and the application of the Kolbe reaction of dioic acids to give alkyl branches at different positions of the chain... 

Van Veldhoven, P.P., Huang, S., Eyssen, H.J. Mannaerts, G.P. (1993)7. Inker. Metab. Dis. 16, 381-391. The deficient degradation of synthetic 2- and 3-methyl-branched fatty acids in fibroblasts from patients with peroxisomal disorders. 

Croes, K. (1998) ActaBiomedicaLovaniensia 165 (Ph.D. thesis—Leuven University Press). a-Oxidation of 3-methyl-branched fatty acids A revised pathway. 

---