TABLE 2.

Comparison of the percentage of secondary-structure components of wt TTR obtained from FTIR spectra collected at 25°C, 18 h after high-temperature treatment at 25°C, and 18 h after decompression at the specified temperatures and pD values

Secondary-structure content of wt TTR after various treatments
	After high-pressure treatment				After high-temperature treatment		Native TTR (soluble)	Acidic fibrils
	pD 5.0		pD 7.5		pD 5.0	pD 7.5	pD 7.5
Secondary structure (%)	37°C	5°C	37°C	5°C	25°C	25°C	25°C	Incubated at 37°C, pH 4.4
α-Helix	6	11	5	10	1	4	3	10
Random coil	26	38	35	38	23	22	29	14
Turns	22	26	20	27	21	23	23	32
Native β-sheets		25	40	25	27	32	42	0
1625 cm−1β-sheets	46	0	0	0	0	0	0	44
1686/1616 cm−1β-sheets	0	0	0	0	28	19	3	0
All β-sheets	46	25	40	25	55	51	45	44

Also shown for comparison are the percentages of secondary structure of the fibrils produced at atmospheric pressure at 25°C upon acidification. The error is ±2%.