Alkyldihydroxyacetone phosphate synthase

Peroxisomes contain dihydroxyacetone phosphate acyl-transferase and alkyldihydroxyacetone phosphate synthase, which are involved in synthesis of the plasmalogens (Chapter 19). Peroxisomes may also participate in the biosynthesis of bile acids. The conversion of trihydrox-ycholestanoic acid to cholic acid (Chapter 19) has been localized to peroxisomes. 

The biosynthesis of plasmalogens has been elegantly reviewed by several investigators (Paltauf, 1994 Lee, 1998 Nagan and Zoeller, 2001 Murphy, 2001). Briefly, the first three enzymes of plasmalogen biosynthesis (dihydroxyacetone phosphate acyltransferase, alkyldihydroxyacetone phosphate synthase, and acyl/alkyl dihydroxyacetone reductase) are located in peroxisomes. The other enzymes, namely l-alkyl- n-GroP acyltransferase, l-alkyl-2-acyl-5n-GroP phosphohydrolase, and l-alkyl-2-acyl-jn-Gro ... 

Figure 2. Biosynthesis of plasmalogens in mammalian tissues. Enzymes (1) dihydroxyacetone phosphate acyltransferase (2) 1-acyldihydroxyacetone phosphate synthase (3) 1-alkyldihydroxyacetone phosphate oxidoreductase (4) l-alkyl-5n-glycero-3-phosphate acyltransferase (5) 1-afkyl 2-acyl-5w-glycero-3-phosphohydrolase (6) CDP-ethanolamine transferase (7) l-alkyl-2-acyl-5w-glycero-3-phosphoethanolamine desaturase (8) methyltransferases and base-exchange enzymes. CDP-ethanolamine, cytidine diphosphoethanolamine. CMP, cytidine monophosphate. CoA, coenzyme A. DHAP, dihydroxyacetone phosphate. NADH, nicotinamide adenine dinucleotide, reduced form. NAD, nicotinamide adenine dinucleotide, oxidized form. Pi, phosphate.

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