Figure 2From: Secondary structure of protamine in sperm nuclei: an infrared spectroscopy studyCD spectra of salmine and squid protamine in trifluoroethanol. (A) CD spectra of salmine. (C) CD spectra of squid protamine. The numbers refer to the TFE concentration in percentage by volume. The buffer was 10 mM HEPES, 140 mM NaCl, pH 7.0 at 20°C. Variation of the mean molar ellipticity ([θ], deg.cm2/dmol) at 222 nm with added TFE for salmine (B) and squid protamine (D). The percentage of helical structure, calculated as described in Methods is also indicated.Back to article page