著者

松本 孝 /若林 ゆう /池田 啓一 /山倉 文幸 若林 ゆう 池田 啓一 Keiichi IKEDA Fumiyuki YAMAKURA

出版者

昭和女子大学近代文化研究所

雑誌

學苑 = GAKUEN (ISSN:13480103)

巻号頁・発行日

vol.818, pp.35-39, 2008-12-01

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Peroxynitrite, which is formed from the reaction of superoxide radical and nitric oxide, can cause specific structural modifications in proteins such as the addition of a nitro group onto aromatic residues. These modifications can cause perturbations in the properties of the proteins, such as conformation, catalytic activity, susceptibility to proteolysis, and immunogenicity, resulting in several human diseases. Finding a specific peroxynitrite scavenger is, therefore, of considerable importance. Accordingly, we assessed the scavenging ability of several biomolecules purchased from commercial sources on nitration of a protein by peroxynitrite at physiologic CO2 condition in vitro. In sixteen molecules tested, reduced redox-cofactors, and polyphenol-compounds were effective scavengers against peroxynitrite-mediated protein nitration in vitro and one of these, epigallocatechine was the most effective. It was also noticed that tryptophan and serotonin creatinine sulfate possessed relatively high scavenging abilities against peroxynitrite-mediated protein nitration in vitro.

著者

山岸 美穂 松本 孝 池田 啓一 山倉 文幸 Miho YAMAGISHI Takashi MATSUMOTO Keiichi IKEDA Fumiyuki YAMAKURA

出版者

昭和女子大学近代文化研究所

雑誌

学苑 (ISSN:13480103)

巻号頁・発行日

no.782, pp.53-56, 2005-12

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トリプトファンとペルオキシナイトライトを反応させてからすぐに逆相HPLCで分離させ,ニトロソ化物,ニトロシル化物等不安定な物質を同定することや,前報でトリプトファンの方がチロシンよりも未確認の生成物が多く検出されたということから,これらの未確認生成物を同定することを目的として,実験を進めた。その結果,キヌレニン,7-ニトロトリプトファン,6-ニトロトリプトファン,4-ニトロトリプトファン,5-ニトロトリプトファンが確認された。また,反応直後と数日後の比較から,報告にあるニトロソ化物,ニトロシル化物以外の,不安定な生成物が確認された。

著者

Takeo Imai Katsuhiko Taguchi Yoko Ogawara Daijiro Ohmori Fumiyuki Yamakura Hidenori Ikezawa Akio Urushiyama

出版者

The Japanese Biochemical Society

雑誌

The Journal of Biochemistry (ISSN:0021924X)

巻号頁・発行日

vol.130, no.5, pp.649-655, 2001 (Released:2008-11-18)

参考文献数

32

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An extremely thermostable [4Fe-4S] ferredoxin was isolated under anaerobic conditions from a hyperthermophilic archaeon Thermococcus profundus, and the ferredoxin gene was cloned and sequenced. The nucleotide sequence of the ferredoxin gene shows the ferredoxin to comprise 62 amino acid residues with a sequence similar to those of many bacterial and archaeal 4Fe (3Fe) ferredoxins. The unusual Fe-S cluster type, which was identified in the resonance Raman and EPR spectra, has three cysteines and one aspartate as the cluster ligands, as in the Pyrococcus furiosus 4Fe_ferredoxin. Under aerobic conditions, a ferredoxin was purified that contains a [3Fe-4S] cluster as the major Fe-S cluster and a small amount of the [4Fe-4S] cluster. Its N-terminal amino acid se-quence is the same as that of the anaerobically-purified ferredoxin up to the 26th residue. These results indicate that the 4Fe ferredoxin was degraded to 3Fe ferredoxin during aerobic purification. The aerobically-purified ferredoxin was reversibly converted back to the [4Fe-4S] ferredoxin by the addition of ferrous ions under reducing conditions. The anaerobically-purified [4Fe-4S] ferredoxin is quite stable; little degradtion was observed over 20 h at 100°C, while the half-life of the aerobically-purified ferredoxin is 10h at 100°C. Both the anaerobically-and aerobically-purified ferredoxins were found to function as electron acceptors for the pyruvate-ferredoxin oxidoreductase purified from the same archaeon.