pH profile of cytochrome c-catalyzed tyrosine nitration

Autor:	Kei Takemoto, Masafumi Shibamori, Keiki Ogino, Junna Okuda, Norio Kodama, Yoshiaki Hitomi, Tomoko Takigawa, Yasuhiro Kambayashi, Masayuki Kubo
Rok vydání:	2006
Předmět:	biology Cytochrome Cytochrome c peroxidase Nitrotyrosine Cytochrome c Photochemistry Medicinal chemistry General Biochemistry Genetics and Molecular Biology chemistry.chemical_compound chemistry biology.protein Cytochrome c oxidase Nitrite Hydrogen peroxide Peroxidase
Zdroj:	Acta Biochimica Polonica. 53:577-584
ISSN:	1734-154X 0001-527X
Popis:	In the present study, we investigated how cytochrome c catalyzed the nitration of tyrosine at various pHs. The cytochrome c-catalyzed nitration of tyrosine occurred in proportion to the concentration of hydrogen peroxide, nitrite or cytochrome c. The cytochromec-catalyzed nitration of tyrosine was inhibited by catalase, sodium azide, cystein, and uric acid. These results show that the cytochrome c-catalyzed nitrotyrosine formation was due to peroxidase activity. The rate constant between cytochrome c and hydrogen peroxide within the pH range of 3-8 was the largest at pH 6 (37 degrees C). The amount of nitrotyrosine formed was the greatest at pH 5. At pH 3, only cytochromec-independent nitration of tyrosine occurred in the presence of nitrite. At this pH, the UV as well as visible spectrum of cytochrome c was changed by nitrite, even in the presence of hydrogen peroxide, probably via the formation of a heme iron-nitric oxide complex. Due to this change, the peroxidase activity of cytochrome c was lost.
Databáze:	OpenAIRE
Externí odkaz:	https://explore.openaire.eu/search/publication?articleId=doi_________::f4ba0d16f8588efc2c16c71c6ae8487d https://doi.org/10.18388/abp.2006_3330 Zobrazit plný text záznamu