| Project/Area Number |
03454185
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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 |
細菌学
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| Research Institution | Niigata College of Pharmacy |
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Principal Investigator |
TAMURA Akira Niigata College of Pharmacy, Department of Microbiology, Professor, 薬学部, 教授 (50027314)
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| Co-Investigator(Kenkyū-buntansha) |
FUKUHARA Masahiro Niigata College of Pharmacy, Department of Microbiology, Assistant, 薬学部, 助手 (70238509)
OHASHI Norio Niigata College of Pharmacy, Department of Microbiology, Assistant, 薬学部, 助手 (10169039)
URAKAMI Hiroshi Niigata College of Pharmacy, Department of Microbiology, Assistant Professor, 薬学部, 助教授 (80139732)
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| Project Period (FY) |
1991 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥5,100,000 (Direct Cost: ¥5,100,000)
Fiscal Year 1993: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1992: ¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1991: ¥2,400,000 (Direct Cost: ¥2,400,000)
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| Keywords | Rickettsia tsutsugamushi / antigenic type / type-specific antigen / 56-KDa protein / virulent factor / cloning and sequencing of gene / PCR / restriction enzyme fragment polymorphism / 恙虫病 / 型特異抗原 / R.tsutsugamushi / 遺伝子クロ-ニング / 病原性 / 恙虫病診断 / シグナルペプチド |
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| Research Abstract |
Various antigenic variants are recognized in Rickettsia tsutsugamushi, and our previous studies indicated the relationship between the antigenic type of this rickettsia and its virulence to mice. Because the antigenic variety of this microorganism is due to the type-specific antigen of 56-KDa protein located on the rickettsial surface, the difference of virulence in each strain seems to depend on the molecular structure of this protein. In this study, the whole molecular structure of 56-KDa proteins originated from high-virulent strains of Gilliam, Karp and Kato, and from low-virulent strains of Kawasaki, Kuroki and Shimokoshi, were determined by chemical analysis of purified 56-KDa proteins, and by cloning and sequencing methods of 56-KDa protein genes, and the structures were compared among the strains. The results obtained are as follows :
(1) the proteins consisted of 521-532 amino acids (corresponding to 55308-56745 dalton),
(2) a putative signal peptide consisting of 22 amino acids was recognized at the N-terminal end,
(3) transcription of the gene is regulated by several tandem promoters,
(4) the homologies of these proteins among the six strains varied from 60 to 82% in the amino acid sequences,
(5) 4 variable domains with spans of 16-40 amino acids were recognized in the molecules,
(6) 56-KDa protein genes from several newly isolated strains amplified by PCR method showed polymorphism in the restriction enzyme fragment analyzes, and serotype strains of Gilliam, Karp and Kuroki strains were further classified into several subtypes.
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