| Project/Area Number |
09671953
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Conservative dentistry
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| Research Institution | Okayama University |
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Principal Investigator |
KOKEGUCHI Susumu Okayama Univ.Dent.Sch., Assistant, 歯学部, 助手 (10144776)
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| Co-Investigator(Kenkyū-buntansha) |
TAKAHASHI Keiso Okayama Univ.Dent.Sch., Assistant, 歯学部, 助手 (70243475)
NISHIMURA Fusanori Okayama Univ.Dent.Sch., Associate Professor, 歯学部附属病院, 講師 (80208222)
MURAYAMA Yoji Okayama Univ.Dent.Sch., Professor, 歯学部, 教授 (50029972)
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| Project Period (FY) |
1997 – 1998
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| Project Status |
Completed (Fiscal Year 1998)
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| Budget Amount *help |
¥3,000,000 (Direct Cost: ¥3,000,000)
Fiscal Year 1998: ¥1,000,000 (Direct Cost: ¥1,000,000)
Fiscal Year 1997: ¥2,000,000 (Direct Cost: ¥2,000,000)
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| Keywords | Iron / Acquisition / Periodontal Bacteria / Porphyromonas gingivalis / Actinobacillus actinomycetemcomitans |
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| Research Abstract |
Iron, an essential bacterial nutrient, is not freely available for bacteria in vivo because iron is complexed with host iron-binding proteins such as transferrin, lactoferrin and hemoglobin. However, pathogenic bacteria develop specific iron-uptake systems including the production of specific cellular iron binding proteins to acquire iron in vivo. For periodontal bacteria, little is known about their iron-uptake system. In this study, we determined the genes for iron uptake in periodontal bacteria, Actinobacillus actinomycetemcomitans and Porphyromonas gingivalis. The following results were obtained.
1) A.actinomycetemcomitans :
The two ferritin genes were found in the upstream of a regulatory gene, actX of A.actinomycetemcomitans Y4. Ferritin is a bacterial iron binding protein, which acts iron acquisition and storage in bacterial cells. The ferritin genes in A.actinomycetemcomitans Y4 were cloned and their DNA sequence analyses were performed. They are consisted of 486 bp (161 amino ac
… More
ids) and 498 bp(165amino acids) open reading frames. They exhibited 80 % and 85 % homology with Haemophilus influenzae ferritin genes. The Western blotting analysis showed the two cellular proteins(approximately 20kDa), reacted with anti-Escherichia coli ferritin rabbit serum were expressed in A.actinomycetemcomitans Y4 cells.
2) P.gingivalis :
P.gingivalis requires hemin for its growth. The putative hemin biding protein genes were determined for P.gingi va/is by polymerase chain reaction method. The oligonucleotide primers for the PCR were designed from the Bacteroides fragilis hemin-uptake protein gene(hupA). Approximate 1.3-kb DNA fragments were amplified from P.gingivahs FDC 381 genomic DNA and the DNA sequences were analyzed. The partial DNA sequences of the amplified DNA fragments showed high homologies with the P.gingi valis hemagglutinin gene and protease genes. These results indicate that P.gingivalis might capture to erythrocytes and decompose them to acquire hemin by these gene products. Less
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