| Project/Area Number |
17590376
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Parasitology (including Sanitary zoology)
|
|---|
| Research Institution | Keio University |
|---|
Principal Investigator |
TAKASHI Asai Keio University, School of Medicine, Assistant Professor (50175163)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MAEDA Takuya The University of Tokyo, The Institute of Medical Science, Research Associate (20383763)
|
|---|
| Project Period (FY) |
2005 – 2007
|
| Project Status |
Completed (Fiscal Year 2007)
|
| Budget Amount *help |
¥3,280,000 (Direct Cost: ¥3,100,000、Indirect Cost: ¥180,000)
Fiscal Year 2007: ¥780,000 (Direct Cost: ¥600,000、Indirect Cost: ¥180,000)
Fiscal Year 2006: ¥1,200,000 (Direct Cost: ¥1,200,000)
Fiscal Year 2005: ¥1,300,000 (Direct Cost: ¥1,300,000)
|
|---|
| Keywords | Glycolytic Pathway / Hexokinase / Pyruvate Kinase / Phosphoglucomutase / Parasitic Protozoa / Toxoplasma gondii / Mitochondria / Apicoplast / 寄生虫 / 遺伝子組換酵素 / グルコース6-リン酸 / 系統樹解析 |
|---|
| Research Abstract |
A regulation mechanism of glycolytic pathway in Toxoplasma gondii is very simple. The initial product, glucose 6-phosphate, acts on an allosteric activator for pyruvate kinase and determines the flow rate. Other tentative key enzymes, hexokinase and phosphofructokinase, have no regulation properties. This is very surprising event because host organisms like human have very complicated some regulation mechanisms. In the process of this research, we have identified a novel pyruvate kinase whose physiological role is unknown. This enzyme use GDP as a substitute far ADP for the enzyme reaction. The pH optimal of this enzyme is in higher position and the enzyme is present in the mitochondrion and the apicoplast. There are no organisms except Toxoplasma gondii have the pyruvate kinase in mitochondrion up to date. A participation of this enzyme to the glycolytic pathway of Toxoplasma gondii is still unknown. The presence of this enzyme in the mitochondrion and the apicoplast has been extensively studied by using the some deletion mutants of N-terminal of this enzyme (J. Biol. Chem. in press). The physiological function of this enzyme is a future project to be solved. From the fact that glucose 6-phosphate is the most important substance for the glycolitic pathway of Toxoplasma gondii, we have made a recombinant protein for phosphoglucomutase that use glucose 6-phosphate as a substrate, and investigated some properties of phosphoglucomutase. Amino acid alignment analysis indicated that Toxoplasma gondii phosphoglucomutase was closely related to plant enzymes, and faraway to bacteria enzymes and closely related species, Plasmodium enzymes. There are no conspicuous properties in Toxoplasma gondii phosphoglucomutase but sensitiveness for the bivalent cation is quite different to other organism enzymes. We will report the properties of phosphoglucomutase in Toxoplasma gondii in the near future.
|
