FIGURE 6.
Raman spectra of HGD and R14C in the fingerprint region at pH 4.5. Compared to HGD (black curve), the secondary structure of R14C is essentially unchanged in all states of thiol oxidation: R14C solution with little or no oxidation (red curve), R14C solution with less than half the thiols oxidized (green curve) and R14C aggregates in the solid phase with about half the thiols oxidized (pink curve). Intensities in this region are normalized with respect to the phenylalanine band at 1003 cm−1, but cannot be compared quantitatively for the different samples due to variations in their individual backgrounds.