No abstract

No abstract

internally hydrogen-bonded configuration; and that in bradykinin it spends more time in that configuration. In other words, the secondary structure of these peptides as revealed by CD is a time average of two rapidly interconnecting structures-a disorder structure and a partially ordered one in which a proline residue is internally hydrogen bonded. Given this hypothesis, the CD spectrum of bradykinin was simulated assuming that one of its proline residues spends a quarter of its time internally hydrogen bonded over and above the time spent in that configuration in the analog. Simulation was accomplished by adding to the CD spectrum of the analog the normalized spectrum of two moles of acetylphenylalanin-