Synthesis of alkyl-ether glycerophospholipids in rat glomerular mesangial cells: evidence for alkyldihydroxyacetone phosphate synthase activity.
We studied the ability of rat glomerular mesangial cells and their microsomal fractions to incorporate 1-[14C]hexadecanol to glycerophospholipids via an O-alkyl ether linkage and assessed the presence and activity of the required enzyme: alkyl-dihydroxy acetone phosphate synthase. Suspensions of cultured mesangial cells incorporated 1-[14C]hexadecanol to the phosphatidyl ethanolamine and phosphatidyl choline lipid pools, via a bond resistant to acid and base hydrolysis. When cell homogenates or microsomal fractions were incubated with palmitoyl-DHAP and 1-[14C]hexadecanol, alkyl-DHAP and 1-O-alkyl glycerol were formed (alkyl:hexadecyl). The activity of the enzyme responsible for the O-alkyl product formation was calculated to be 2.5 +/- 0.3 and 544 +/- 50 pmoles/min/mg protein for mesangial cell homogenates and mesangial cell microsomes, respectively. These observations provide evidence that mesangial cells may elaborate either linked lipid precursors de novo for the biosynthesis of O-alkyl glycerophospholipids.
D019883:Alkyl and Aryl Transferases; D000818:Animals; D000001:Calcimycin / Q000494:pharmacology; D002250:Carbon Radioisotopes; D004987:Ethers / Q000096:biosynthesis*; D005233:Fatty Alcohols / Q000378:metabolism; D066298:In Vitro Techniques; D007678:Kidney Glomerulus / Q000166:cytology / Q000201:enzymology*; D008297:Male; D010713:Phosphatidylcholines / Q000096:biosynthesis*; D010714:Phosphatidylethanolamines / Q000096:biosynthesis*; D051381:Rats; D011919:Rats, Inbred Strains; D014166:Transferases / Q000378:metabolism*
D002250:Carbon Radioisotopes; D004987:Ethers; D005233:Fatty Alcohols; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D000001:Calcimycin; C005031:cetyl alcohol; D014166:Transferases; D019883:Alkyl and Aryl Transferases; C019654:alkylglycerone-phosphate synthase