Conformation of horse heart ferricytochrome c. III. Comparative optical rotatory dispersion study of the protein with its derivative heme undecapeptide
✍ Scribed by P. Saludjian; E. Shechter
- Publisher
- Wiley (John Wiley & Sons)
- Year
- 1967
- Tongue
- English
- Weight
- 713 KB
- Volume
- 5
- Category
- Article
- ISSN
- 0006-3525
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✦ Synopsis
The optical rotatory dispersion of, horse heart ferricytochrome c and of a ferri heme undecapeptide have been determined under various conditions. Analysis of the Soret region makes it possible to characterize three different states of ferricytochrome c: the native state (superposition of a negative and a positive Cotton effect); an intermediate state (single positive Cotton effect whose magnitude A [MI is equal to 55,000); a denatured state (single positive Cotton effect whose magnitude A[M] is equal to 115,000) in which compared to both the native and intermediate states a more or less important decrease in helix content is observed. The optical rotatory dispersion spectra of the Soret region of the monomeric ferri heme undecapeptide is similar to that of denatured ferricytochrome C. The multiplicity of Cotton effects observed under certain conditions for the hemopeptide is a consequence, resrilting from a polymerization, of intermolecular interact'ions. The comparison of the optical rotatory dispersion spectra of ferricytochrome c and the ferri heme rindecapeptide indicates that in the intermediate state interactions remain between the heme group and the port,iori of the polypeptide chain absent in the hemopept.ide. These interactions disappear in the denatured state.
* Part of this work was presented a t the Second International Biophysics Congress, Vienna, September 4-9, 1966. 561
* Subsequent to the completion of this work, a report appeared on the OltD study of a heme octapeptide derived from ferricytochrome c.l0 These results are in good agreement with those we describe here on HP,.