1995 Fiscal Year Final Research Report Summary
Establish of assay methods for fatty acid oxidation enzymes and analysis of trifunctional protein deficiency
| Project/Area Number |
06454175
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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 |
Pathological medical chemistry
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| Research Institution | Shinshu University |
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Principal Investigator |
HASHIMOTO Takashi Shinshu Univ. Sch. of Med. Dept. of Biochem. Professor, 医学部, 教授 (80009935)
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| Co-Investigator(Kenkyū-buntansha) |
KAMIJO Keiju Shinshu Univ. Sch. of Med. Dept. of Biochem. Assistant, 医学部, 助手 (10252074)
FURUTA Shuichi Shinshu Univ. Sch. of Med. Dept. of Biochem. Assistant, 医学部, 助手 (80126705)
MIYAZAWA Shoko Shinshu Univ. Sch. of Med. Dept. of Biochem. Assistant, 医学部, 助手 (20020745)
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| Project Period (FY) |
1994 – 1995
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| Keywords | Mitochondria / Fatty acid oxidation enzymes / Inform error of metabolism |
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| Research Abstract |
We have studies on deficiencies of two new mitochondrial fatty acid oxidation enzymes : very-long-chain acyl-CoA dehydrogenase and enoyl-CoA hydratase/3-hydroxyacyl-CoA dehydrogenase/3-ketoacyl-CoA thiolase trifunctional protein.
1. Mutation analysis of very-long-chain dehydrogenase defieicy was conducted on more than ten patients. The enzyme protein was hardly detectable in most of the patients' fibroblasts by immunoblot analysis. Analysis at the cDNA level, the mutations are heterogeneous.
2. Human enzymes having the activities of enoyl-CoA hydratase, 3-hydroxyacyl-CoA dehydrogenase, and 3-ketoacyl-CoA thiolase were purified, and chracterized, because it is necessary to study about trifunctional protein deficiency. During this study, we found new enoyl-CoA hydratase and 3-hydroxyacyl-CoA dehydrogenase.
3.Trifunctional protein is an enzyme complex composed of alpha-subunit with the hydratase and dehydrogenase domains and beta-subunit with the thiolase domain. Trifunctional protein deficiency is classified into two groups. In one more common group, the enzyme protein is present and only the dehydrogenase activity is deficient. In most patients of this group, G1528C mutation in the dehydrogenase domain was confirmed. In the second group, the level of the enzyme protein was extremely low and all three enzyme activity are undetectable. We have studied about a mechanism of loss of enzyme protein, and shown that newly synthesized precursors of the subunits were transported into mitochondria, and processed to the mature forms, but these polypeptides are rapidly degraded without formation of the enzyme complex.
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