Concept #1: Factors that Disrupt Alpha Helix Structure

Practice: Why does poly-L-Glutamate adopt an α-helical structure at low pH but a random conformation above pH 5?

Concept #2: Gly and Pro Disrupt Alpha Helices

Practice: Which of the following peptides is more likely to take up an α-helical structure and why?

Practice: An α-helix would be destabilized most by:

Practice: At pH 6.8, which of the following peptides is least likely to form an α-helix?

Peptide # 1: RSEDNFGAPKSILWE                    Peptide # 2: DQKASVEMAVRNSGK

Practice: Why does proline often “break” an alpha helix?