1987 Fiscal Year Final Research Report Summary
Phospholipid Asymmetry of the Biological Membranes and it's Modification
| Project/Area Number |
61560102
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
応用生物化学・栄養化学
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| Research Institution | Saga University |
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Principal Investigator |
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| Co-Investigator(Kenkyū-buntansha) |
YAMAMOTO Kyosuke SAGA MEDICAL SCHOOL, 内科, 講師 (00117285)
ENOMOTO Noriyuki SAGA UNIVERSITY, 農学部, 教授 (20039308)
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| Project Period (FY) |
1986 – 1987
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| Keywords | Lipid asymmetry / Phospholipid biosynthesis / Structure and function of membranes / Regulation of CTP / シチジリルトランスフェラーゼ活性調節 |
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| Research Abstract |
The present study was undertaken to understand the factors influencing on the metabolic regulation of phospholipid asymmetry in the biological membranes. At first, we have found that phospholipase C from Cl Welchii and trinitrobenzene sufonate were reasonable probes for the analysis of lipid asymmetry in the biological membranes. By using these probes, we have studied the effects of dietary ingtredients, hormones or drugs on the phospholipid distribution and metabolism of the liver microsomal bilayer in the rat.
From these experiments, it was suugested that the changes in the quantity and quality of microsomal phospholipids by these experimental conditions did not effect on the phospholipid distribution of the microsomal bilayer. THus, phosphatidylcholine distributed predominantly on the cytoplasmic face of the microsomal bilayer and phosphatidylethanolamine distribured predominantly on the lumenal face of the microsomal bilayer. In addition, there were similar molecular species and fatty acid composition of individual phospholipid in each bilayer. However, the distribution of newly synthesized phospholipids was predominantly located on the cytoplasmic face of the bilayer.
Administration of clofibrate or DEHP enhanced the hepatic phospholipid synthesis and increased the activity of microsomal CTP:phosphocholine cytidylyltransferase, the rate-limiting enzyme for phosphatidylcholine biosynthesis. Preferential hydrolysis of phospholipids on the cytoplasmic face of the microsomal membranes decreased the activity of CTP:phosphocholine cytidylyltransferase, suggesting that there is close relationship between the activity of membrane-bound enzyme and the microenvironment of the biological membranes.
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