著者

平岡 行博

出版者

松本歯科大学学会

雑誌

松本歯学 (ISSN:03851613)

巻号頁・発行日

vol.32, no.2, pp.117-127, 2006-08-31

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Porphyromonas gingivalis is a major etiological agent implicated in adult periodontitis. The survival of this organism in the periodontal pocket would require an ability to overcome oxidative stress induced by reactive oxygen species generated by neutrophils or exposure to free oxygen from blood. An antioxidant enzyme that may contribute to the survival strategy of this organism is superoxide dismutase (SOD). P. gingivalis has a characteristic SOD which is called "cambialistic SOD" from the Latin cambialis, suggesting change and denoting enzymes capable of making a cofactor substitution. We prepared a mutant P. gingivalis SOD that possessed a mutation of the amino acids near the active-metal by site-directed mutagenesis, and discussed the structural basis of the metal-specific activity. SODs distribute in three primary domain, Bacteria, Eucarya, and Archaea, then the survival strategy of P. gingivalis seems to be an evolutional strategy of early life in remote ages.