Figure 4.

Changes of different secondary structural contents of incubated insulin over time, as obtained from the curve-fitting analysis of Raman amide I band (Table 1). Panel (A) shows the changes in the secondary structural component (%) against incubation time: helix (orange), β-sheet (brown), loose β-strand, PPII and disordered (light green), and other undefined component (deep green). Panel (B) shows the changes in the Raman intensity of the special helical marker band at 940 cm^–1 at different time points of incubation. The Raman intensity at 1449 cm^–1 was used as a reference.