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oai:kanazawa-u.repo.nii.ac.jp:00053795 2024-06-20T06:03:03Z 934:935:937

The Role of Lipophilic Quinones in the Electron Transport System of Escherichia coli 板垣, 英治 Itagaki, Eiji 15540 A pale-brown powder preparation of the particulate fraction of E. coli cells grown with nitrate respiration was obtained with cold acetone treatment. This preparation, was similar to the solubilized and partially purified enzyme preparation, had high activities of for-mate dehydrogenase and nitrate reductase and contained cytochrome b1, but no activity of formate-nitrate reductase system. By addition of lipids prepared from this organism with aid of a detergent, PADA, the activity of formate-nitrate reductase system was completely restored. The restoration efficiencies of enzyme activity by UQ8 and K2 which were quinones found in this organism, were 2.6 to 1 per mole. The experiments with the UQ8, K2 or both specifically deprived, and ultraviolet irradiated lipid preparations showed that UQ8, rather than K2, acted more effectively as an electron carrier. UQ8 was anaerobically reduced slowly by the enzyme preparation wit formate, and UQ8H2 was rapidly oxidized by nitrate with simultaneous production of stoichiometric amounts of nitrite. From these results, it is concluded taht UQ8 acts principally as hydrogen acceptor for formate dehydrogenase of E. coli. The author is very grateful to Professer R. Sato of this laboratory for his helpful advice, to Mr. T. Fujita of his continous discussion to this work, to Dr. S. Ikeda of the Faculty of Science, Osaka University for his helpful advice to the synthesis of PADA, to Dr. K. Tanaka of Takeda Pharmaceutical Industries Ltd., Osaka and Dr. K. Uehara of the Pharmac-eutical Faculty of Osaka University for materials, and to Dr. K. Kusai of Nagase Sangyo Co. Ltd. for large culture of the organism. journal article The Japanese Biochemical Society 日本生化学会 1964 VoR application/pdf The Journal of Biochemistry 4 55 432 445 AA00694073 0021-924X https://kanazawa-u.repo.nii.ac.jp/record/53795/files/SC-PR-ITAGAKI-E-55_432.pdf https://doi.org/10.24517/00060076 http://hdl.handle.net/2297/00060076 https://kanazawa-u.repo.nii.ac.jp/records/53795 eng http://www.jbsoc.or.jp/ http://www.jbsoc.or.jp/ https://academic.oup.com/jb https://academic.oup.com/jb https://www.jstage.jst.go.jp/browse/biochemistry1922/-char/ja https://www.jstage.jst.go.jp/browse/biochemistry1922/-char/ja Copyright © The Japanese Biochemical Society 日本生化学会