1992 Fiscal Year Final Research Report Summary
Research of Toxoplasma specific enzyme (practical use for diagnosis)
| Project/Area Number |
03670203
|
|---|
| Research Category |
Grant-in-Aid for General Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
寄生虫学(含医用動物学）
|
|---|
| Research Institution | Keio University, School of Medicine (1992)
Tokyo Medical University (1991) |
|---|
Principal Investigator |
ASAI Takashi Keio University, School of Medicine, Department of Tropical Medicine and Parasitology, Instructor, 医学部, 助手 (50175163)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
MIURA Satoshi Yokohama City University, School of Medicine, RI Center, Associate Professor, 医学部, 助教授 (60157427)
|
|---|
| Project Period (FY) |
1991 – 1992
|
| Keywords | Parasite / Protozoa / Toxoplasma gondii / Biochemistry / Enzyme / NTPase / Serodiagnosis |
|---|
| Research Abstract |
Two NTPase isozymes (I,II) were purified from the trophozoites of Toxoplasma gonii (RH) and its in vitro culture fluid by using a high performance liquid chromatography. Then the Michaelis-Menten kinetic constants for ATP and ADP were determined to compare the difference between the isozymes. The Vmax value ration for ATP and ADP of NTPase-I was 150, and that of NTPase-II was 1.1 , respectively. The Km value ratio for ATP and ADP of NTPase-I was 0.12, and that of NTPase-II was 1, respectively. The results indicated that NTPase-I preferred ATP to ADP and NTPase-II hydrolyzed both substrates at almost same rate. The properties of NTPase-II were present to all Toxoplasma strains as surveyed. Therefore, it is supposed that NTPase-II is a good antigen for serodiagnosis. However, we could not identify the antigenic difference between NTPase-I and NTPase-II by double-immunodiffusion, neutralization and western-blotting analysis. The data strongly suggest that both isozymes have a same epitope in their molecules and the epitope is a main antigenic site. Using NTPase for serodiagnosis, it is not necessary to consider the isozyme type which depends on the strain. Because anti-NTPase antibody increased specifically at acute phase infection of Toxoplasma, it was supposed that NTPase should be present mainly to fast-dividing tachyzoite form. This was confirmed by comparing the NTPase contents between tachyzoite and chronically infected bradyzoite. For practical use of NTPase to serodiagnosis, the results were already published by Journal Clinical Microbiology, May, 1992. Other results are now under preparation.
|
