ATP-independent acyl-CoA synthesis in mammalian tissues

• Project/Area Number: 05808059
• Research Category: Grant-in-Aid for General Scientific Research (C)
• Allocation Type: Single-year Grants
• Research Field: Functional biochemistry
• Research Institution: Teikyo University
• Principal Investigator: TAKAYUKI Sugiura Teikyo University, Fac.of Pharmaceu.Sci.Lecturer, 薬学部, 講師 (40130009)
• Co-Investigator(Kenkyū-buntansha): KONDO Sachiko Teikyo University, Fac. of Pharmaceu.Sci.Research Associate, 薬学部, 教務職員 ; 伊藤 清子 帝京大学, 薬学部, 助手 (30241277)
• Project Period (FY): 1993 – 1994
• Project Status: Completed (Fiscal Year 1994)
• Budget Amount: ¥1,900,000 (Direct Cost: ¥1,900,000); Fiscal Year 1994: ¥700,000 (Direct Cost: ¥700,000); Fiscal Year 1993: ¥1,200,000 (Direct Cost: ¥1,200,000)
• Keywords: acyl-CoA / CoA / transacylation / desaturation / chain elongation / phosphatidylinositol / phosphatidylcholine / membrane phospholipids

Research Abstract

Substantial amounts of acyl-CoA were formed when microsomes from several rat tissues were incubated with varying concentrations of free CoA and bovine serum albumin. even in the absence of ATP and Mg^<2+>. No appreciable amount of acyl-CoA was formed from free fatty acid or from boiled microsomes under the same experimental conditions. These observations indicate that acyl-CoA is formed from microsomal lipids by an enzyme activity distinct from previously known long chain fatty acyl-CoA synthase. Phosphatidylinositol and phosphatidylcholine appear to be preferred substrates. It seems possible that CoA-mediated cleavage of phospholipids/ATP-independent acyl-CoA synthesis is implicated in the metabolism of certain types of fatty acyl residues of membrane phospholipids in mammalian cells. In fact, we found that certain species of fatty acyl chains of microsomal lipids from rat hepatocytes underwent desaturation when the microsomal fraction was incubated with CoA and NADH.In contrast to esterified fatty acids, negligible change was observed for free fatty acids under the same experimental conditions. These results provide the evidence that the pathway of CoA-dependent/ATP-independent modification of fatty acyl chains is sufficiently active to account for the desaturation and chain elongation of fatty acids esterified in membrane lipids, especially phospholipids, of living cells.

Research Products

• [Publications] Sugiura,T.et al.: "Coenzyme A-dependent cleavage of membrane phozpholipids in sererdl rat tissues:ATP-independent acyl-CoA synthesis and the generation of lysophopholipids" Biochim.Biophys.Acta. (in press).
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Sugiura,T.et al.: "Coenzyme A-dependent modification of fatty acyl chains of rat liver membrane phozpholipids:possible involvement of ATP-independent acyl-CoA Synthesis" J.Lipid Res.(in press).
  • Description: 「研究成果報告書概要(和文)」より
• [Publications] Sugiura, T., Kudo, N., Ojima, T., Mabuchi-Itoh, K., Yamashita, A.and Waku, K.: "Coenzyme A-dependent cleavage of membrane phospholipids in several rat tissues : ATP-independent acyl-CoA synthesis and the generation of lysophospholipids" Biochim. Biophys. Acta. (in press). (1995)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Sugiura, T., Kudo, N., Ojima, T., Kondo, S.Yamashita, A., and Waku, K.: "Coenzyme A-dependent modification of fatty acyl chains of rat liver membrane phospholipids : possible involvement of ATP-independent acyl-CoA synthesis" J.Lipid Res.(in press). (1995)
  • Description: 「研究成果報告書概要(欧文)」より
• [Publications] Sugiura,T.et al.: "Coenzyme A.dependent cleavage of membrane phospholipids in several rat tissues:ATP-independent acyl-CoA Synthesis" Biochim.Biophys.Acta. (in press).
• [Publications] Sugiura,T.et al.: "Coenzyme A-dependent modification of fatty acyl chains of rat river membrane phospholipids" K.Lipid Res.(in press).