Characterization of hyperfine-shifted 1H resonances in oxidized and reduced putidaredoxin, an Fe2S2 ferredoxin from Pseudomonas putida
✍ Scribed by Gayathri Ratnaswamy; Thomas C. Pochapsky
- Book ID
- 102527770
- Publisher
- John Wiley and Sons
- Year
- 1993
- Tongue
- English
- Weight
- 460 KB
- Volume
- 31
- Category
- Article
- ISSN
- 0749-1581
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✦ Synopsis
Abstract
Hyperfine‐shifted ^1^H resonances in the two accessible oxidation states of putidaredoxin (Pdx), an Fe~2~S~2~ ferredoxin from Pseudomonas putida, were observed and their temperature dependence and relaxation times measured using rapid‐recycle NMR methods. As with other Fe~2~S~2~ ferredoxins, the hyperfine‐shifted resonances observed in oxidized (Fe^3+^−Fe^3+^) Pdx exhibit anti‐Curie behavior, their signals moving away from the diamagnetic region with increasing temperature. The hyperfine‐shifted resonances of reduced Pdx (Fe^3+^−Fe^2+^) exhibit Curie‐type behavior, and closely resemble the appearance and behavior of the hyperfine shifted resonances of human ferredoxin (HFdx), with which Pdx shares significant sequence and functional homology. Electron self‐exchange is slow on the ^1^H chemical shift time‐scale, as half‐reduced samples of Pdx exhibit hyperfine‐shifted resonances characteristic of both forms.