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The location of the polyphosphate-binding sites on cytochrome <em>c</em> measured by NMR paramagnetic difference spectroscopy.
- Source :
-
European Journal of Biochemistry . 8/1/91, Vol. 199 Issue 3, p569-574. 6p. - Publication Year :
- 1991
-
Abstract
- Analyses of unimolecular electron self-exchange reactions provide a comparatively simple and direct approach to understanding biological electron transfer. Such studies are currently limited by a lack of well characterised aggregating systems. In the presence of sodium hexametaphosphate, cytochrome c forms stable protein aggregates as a result of binding hexametaphosphate at a single site on its surface (preceding paper in this issue of the journal). Here we report the location of the principal polyphosphate binding site on the surface of cytochrome c for both hexametaphosphate and a second polyphosphate, tripolyphosphate determined using 1H-NMR spectroscopy in conjunction with the relaxation probe potassium hexacyanochromium(III). Addition of either hexametaphosphate or tripolyphosphate to ferricytochrome c in the presence of the relaxation probe causes a decrease in intensity of several resonances in the paramagnetic difference spectrum, including Phe82 ortho/meta, I1e85 δ methyl and Ile9 γ methyl. Together these effects put the site of polyphosphate binding close to lysines 13, 86, and 87. Additionally the effect of sodium tripolyphosphate and sodium trimetaphosphate on cytochrome c aggregation is described. The potential role of this site in anion-induced cytochrome c aggregation is discussed. [ABSTRACT FROM AUTHOR]
- Subjects :
- *CHEMICAL reactions
*CYTOCHROMES
*POTASSIUM
*AMINO acids
*UNIMOLECULAR reactions
Subjects
Details
- Language :
- English
- ISSN :
- 00142956
- Volume :
- 199
- Issue :
- 3
- Database :
- Academic Search Index
- Journal :
- European Journal of Biochemistry
- Publication Type :
- Academic Journal
- Accession number :
- 13698863
- Full Text :
- https://doi.org/10.1111/j.1432-1033.1991.tb16156.x