Molecular Biological and Biochemical Studies on the Control Mechanism of Blood Coagulation and Fibrinolysis
| Project/Area Number |
61480459
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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 | Niigata University |
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Principal Investigator |
KOIDE Takehiko Niigata University School of Medicine, 医学部, 講師 (60018695)
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| Co-Investigator(Kenkyū-buntansha) |
ODANI Shoji Niigata University School of Medicine, 医学部, 講師 (60018702)
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| Project Period (FY) |
1986 – 1988
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥7,200,000 (Direct Cost: ¥7,200,000)
Fiscal Year 1988: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1987: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 1986: ¥5,000,000 (Direct Cost: ¥5,000,000)
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| Keywords | Control of Blood Coagulation / Histidine-rich glycoprotein / HRG / Heparin / Heparin-binding site / Dextran sulfate / Protein C inhibitor / Zn^<2+> / 血液凝固の制御機構 / 高ヒスチジン糖タンパク質遺伝子 / 遺伝子構造 / シスタチンスーパーファミリー / 分子進化 / ヘパリンコファクターII / 硫酸化多糖 / 血液凝固 / 線溶制御 / 遺伝子クローニング / ホモロジー |
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| Research Abstract |
1. Histidine-rich glycoprotein (HRG) is a plasma protein which is considered to function as a control factor in the blood coagulation and fibrinolytic system. The complete nucleotide sequence (2067 base-pairs) of cDNA for HRG was determined. The derived amino acid sequence of HRG revealed that HRG is composed of multi-domain structures, each of which may have an independent function. The detailed sequence study of HRG showed that HRG evolutionarily belongs to the cystatin (cysteine proteinase inhibitors) superfamily.
2. Genomic fragments of HRG were isolated and partially characterized. The gene is about 11 kilobases in length and contains nine exons and eight introns. Locations of the introns in the gene coding for cystatin domains are identical with those of the cystatin supergene family. The gene was localized in chromosome 3.
3. Heparin neutralizing ability of HRG was found to augment in the presence of Zn^<2+>. The N-terminal fragment containing two cystatin domains was isolated by limited proteolysis with chymotrypsin and identified as the heparin-binding and neutralizing domain.
4. The new knowledges obtained on the structure and function of heparin-dependent anticoagulant and antifibrinolytic factors are as follows: 1) Cysteine-47 in the abnormal antithrombin III "Toyama" forms a mixed disulfide bond with a free cysteine in plasma. 2) Interaction of thrombin with heparin is more essential than that of heparin cofactor II in the heparin-dependent thrombin inhibition by heparin cofactor II. 3) Among the dextran sulfate with various sizes and S contents, the molecular species with Mr10,000 and 18% S is best as a cofactor of protein C inhibitor.
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Report
(4 results)
Research Products
(48 results)
