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Published on: September 26, 2016
Two-dimensional pulsed electron spin resonance characterization of 15N-labeled archaeal Rieske-type ferredoxin
Toshio Iwasaki1, Rimma I Samoilova, Asako Kounosu
1Department of Biochemistry and Molecular Biology, Nippon Medical School, Sendagi, Tokyo 113-8602, Japan. tiwasaki@nms.ac.jp
Abstract:
Two-dimensional electron spin-echo envelope modulation (ESEEM) analysis of the uniformly (15)N-labeled archaeal Rieske-type [2Fe-2S] ferredoxin (ARF) from Sulfolobus solfataricus P1 has been conducted in comparison with the previously characterized high-potential protein homologs. Major differences among these proteins were found in the hyperfine sublevel correlation (HYSCORE) lineshapes and intensities of the signals in the (++) quadrant, which are contributed from weakly coupled (non-coordinated) peptide nitrogens near the reduced clusters. They are less pronounced in the HYSCORE spectra of ARF than those of the high-potential protein homologs, and may account for the tuning of Rieske-type clusters in various redox systems.
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