Age-related decline in the activites of erythrocyte membrane adenylate cyclase and protein kinase.

The circular dichroism and thermal denaturation properties of chromatin isolated from duck erythrocytes have been carefully examined as has the chromatography of sonicated erythrocyte chromatin on ECTHAM-cellulose. The circular dichroism spectrum and thermal denaturation profile resemble much more closely those of chromatin from liver than has been previously reported by other workers. The chromatography of erythrocyte chromatin on ECTHAM-cellulose gave results that differ dramatically from those obtained from chromatography of f1-containing chromatins on this weak anion exchanger, in that no variations in histone content, circular dichroism spectra or thermal denaturation profiles were observed in the eluted material. Coupled with our earlier finding of no variation in relative content of individual histones (Reeck, G. R. et al. (1974) Eur. J. Biochem. 49, 407–414), we interpret the results of ECTHAM-cellulose chromatography of erythrocyte chromatin to indicate that f2c-depleted regions analogous to the f1-depleted regions found in f1-containing chromatins do not exist in duck erythrocyte chromatin.