EFFECT OF TEMPERATURE UPON THE CIRCULAR DICHROISM OF BRADYKININ

Abstract

Analysis of the effect of temperature on the circular dichroism spectrum of bradykinin has led to a more precise understanding of the solution conformation of the peptide. Circular dichroism and ¹³C n.m.r. have been used in a complementary fashion to support the picture that bradykinin spends a maximum of about 20% of its time in a partially ordered conformation featuring a γ‐turn with Pro⁷ as the second residue. Since the γ‐turn probability is insensitive to temperature, some other conformational effect dominated by the structure of water presumably produces the pronounced change in the circular dichroism spectrum with increasing temperature.