Hideo Yamasaki1, Yasuko Sakihama1
1Laboratory of Cell and Functional Biology, Faculty of Science, University of the Ryukyus, Nishihara, Okinawa 903-0213, Japan
Tóm tắt
We examined the ability of plant nitrate reductase (NR) to produce nitric oxide (NO) using in vitro assays. Electrochemical and fluorometric measurements both showed that NO is produced by corn NR in the presence of nitrite and NADH at pH 7. The NO production was inhibited by sodium azide, a known inhibitor for NR. During the reaction, absorbance of 2′,7′‐dichlorodihydrofluorescein increased markedly. This change was completely suppressed by sodium azide, glutathione or depletion of oxygen. We conclude that plant NR produces both NO and its toxic derivative, peroxynitrite, under aerobic conditions when nitrite is provided as the substrate for NR.
