Figure 3.

Titration of HK peptides. After the pH of the HK peptide solutions (0.1 mg/ml polymer solution in 0.1 N NaCl) was adjusted to 4.5, 10 μl (10⁻³ mEq) aliquots of 0.1 N NaOH was then sequentially added to 12 ml, and pH changes were recorded. The data represent the mean of duplicate experiments. (A) H³K4b and H³K4bT; and (B) H²K4b and H²K4bT. Open circles represent HK peptides with a histidine-rich tail.