1990 Fiscal Year Final Research Report Summary
Regulation of Gene Expression of Fatty Acid Synthetase in Euglena
| Project/Area Number |
63480491
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
物質生物化学
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| Research Institution | The University of Tokyo |
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Principal Investigator |
KAWAGUCHI Akihiko Tokyo University , College of Arts and Sciences, Professor, 教養学部, 教授 (80013332)
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| Co-Investigator(Kenkyū-buntansha) |
OZEKI Yoshihiro Tokyo University, College fo Arts of Sciences, Assistant Professor, 教養学部, 助手 (50185592)
YAMADA Mitsuhiro Tokyo University, College of Arts and Sciences, Professor, 教養学部, 教授 (50012266)
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| Project Period (FY) |
1988 – 1990
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| Keywords | Fatty acid synthetase / Acyl carrier protein / Euglena / Chlorella / Desaturation |
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| Research Abstract |
Fatty acid synthetase (Type 1) was purified from a mutant of Euglena gracilis which is defective in the function of chloroplasts. Purification was carried out by ammonium sulfate and hydroxyapatite treatments. This fatty acid synthetase was not stable and its activity was lost during the purification. Several reagents tested did not prevent the lost of the activity.
We investigated the effects of CO_2 concentration during growth on the lipid metabolism in Chlorella vulgaris 11h. Major lipids of C. vulgaris was phosphatidylcholine (PC), phosphatidylethanolamine (PE), monogalactosyldiacylglycerol (MGDG) and digalactosyldiacylglycerol (DGDG). The relative contents of lipid classes were essentially the same in high-CO_2 and low-CO_2 cells. However, the degree of unsaturation of fatty acids was higher in low-CO_2 cells than in high-CO_2 cells. The change in the ratio of 18 : 2 to 18 : 3 was particularly significant. The ratio of 18 : 2/18 : 3 in four major lipids was different between high-CO_2 and low-CO_2 cells. The relative differences were markedly greater in galactolipids than in phospholipids. In C. vulgaris, the desaturation of fatty acids bound to MGDG and DGDG occurs in chloroplasts and that of fatty acids bound to PC and PE occurs in endoplasmic reticulum. The former activity was affected by CO_2 concentration more remarkably than the latter activity. It is also suggested that the contributions of chloroplastic and cytoplasmic pathways were different between high-CO_2 and low-CO_2 cells.
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