Electrochemistry of Thioethers as Models for Biological Electron Transfer
Considering the importance of sulfur in biological systems, it is somewhat surprising that thioethers have only recently received attention from the point of view of their redox chemistry. In terms of biological function, there are perhaps three classes of interactions in which they are involved. The first case involves their role as a part of metal centers in redox-active proteins. Examples include cytochrome c where histidine and methionine comprise the two axial ligands in an iron porphyrin, co-factors in methanogenic bacteria F-420 (S-Ni coordination)1 and in the Type I “Blue Copper” proteins.2 Examples of this latter group include azurin and plastocyanin. In the latter case the immediate coordination around Cu(II) is one cysteine thiolate (S at 2.1 Å), two histidine imidazoles (N at 2.05 Å and 2.10 Å), and a methionine sulfur (at 2.9 Å) in a distorted trigonal pyramidal array.
KeywordsElectron Transfer Rate Iron Porphyrin Blue Copper Cysteine Thiolate Spiro Compound
Unable to display preview. Download preview PDF.
- 4.R.A. Marcus and N. Sutin, Biochim. Biophys. Acta 811: 265 (1985).Google Scholar
- 7.D.B. Goodin, A.G. Mauk, and M. Smith, J. Biol. Chem. 262: 7719 (1987).Google Scholar
- 11.S.F. Yang, in: “The Chemistry and Biochemistry of Plant Hormones”, V.C. Runeckles, E. Sondheimer, and D.C. Walton, Academic Press, New York, pp. 131 (1974).Google Scholar
- 12.L.C. Teh, L.J. Murphy, N.L. Huq, A.S. Surus, H.G. Friesen, L. Lazarus, and G.E. Chapman, J. Biol. Chem. 262: 6472 (1987).Google Scholar
- 13.W.R. Fisher, H. Taniuchi, and C.B. Anfinsen, J. Biol. Chem. 248: 3188 (1973).Google Scholar
- 14.H. Wilgus, J.S. Ranweiler, G.S. Wilson, and E. Steliwagen, J. Biol. Chem. 253: 3265 (1978).Google Scholar
- 15.D.P. Root, PhD Dissertation, University of Arizona (1984).Google Scholar