Paramagnetic Inversion of the Sign of the Interference Contribution to the Transverse Relaxation of the Imido Protons of the Coordinated Imidazoles in the Uniformly15N-Labeled Cytochromec3

✍ Scribed by Tomoaki Ohmura; Erisa Harada; Toshimichi Fujiwara; Gota Kawai; Kimitsuna Watanabe; Hideo Akutsu

• Publisher: Elsevier Science
• Year: 1998
• Tongue: English
• Weight: 145 KB
• Volume: 131
• Category: Article
• ISSN: 1090-7807
• DOI: 10.1006/jmre.1998.1378

✦ Synopsis

In the spectrum of uniformly 15 N-labeled cytochrome c 3 , the coordinated imidazole group on oxidation. Cytochrome c 3 relative linewidths of the doublet peaks of the 15 N-coupled imido is a tetraheme protein of a sulfate-reducing bacterium. All proton of the coordinated imidazole group were reversed on oxidathe hemes take the low spin state. The heme irons are diation. This inversion was explained by the interference relaxation magnetic and paramagnetic in the fully reduced and fully process between the electron-proton dipolar and 15 N-1 H dipolar oxidized states, respectively. The inversion of the relative interactions. The inversion can be used to assign the imido protons linewidths was elucidated by the relaxation interference efof the coordinated imidazole groups in heme proteins. ᭧ 1998 fect induced by the paramagnetic center in this paper.