The carbomonoxy derivatives of hemoglobin A and S showed a different optical activity in the Soret region of the spectrum as measured by circular dichroism. Different optical activity was also measured in the carbomonoxy derivatives of the β subunits of hemoglobin A and S, the respective deoxy derivatives showed different circular dichroism spectra only in the presence of inositol hexaphosphate. Sedimentation velocity experiments showed that the differences in optical activity are not due to a different state of aggregation of the subunits. Modification of the tertiary structure of the β subunits seems to be responsible for the phenomenon. Speculation based on the work of Hsu and Woody (Hsu, M.C., and Woody, R.W. (1971) J. Am. Chem. Soc. 93, 3515-3525) suggests the involvement of the β15 tryptophan in the conformational changes produced by the β6 Glu-Val mutation in hemoglobin S.
|Original language||English (US)|
|Number of pages||4|
|Journal||Journal of Biological Chemistry|
|State||Published - Jan 1 1978|
ASJC Scopus subject areas
- Molecular Biology
- Cell Biology