Table 1.

Results of amide I’ deconvolution for native insulin and insulin fibrils formed at pH 1.8 and 7.0. Peak spectral ranges (in agreement with [46,48]) and secondary structure subcomponent contributions are reported.

Protein	Secondary Structure (%)
	Intermolecular β-sheet 1611–1630 cm−1	Intramolecular β-sheet 1615–1638 cm−1	α-helix 1640–1655 cm−1	Disordered/β-turn 1658–1686 cm−1
Native insulin	0	0	60	40
Fibrils pH 7.0	18	56	5	21
Fibrils pH 1.8	76	0	7	17