Spectroscopic Investigations of Pentobarbital Interaction with Transthyretin

Table 2

Percentages of secondary structure components in the amide I and amide II regions of TTR and its pentobarbital complexes.

Bands	TTR free	TTR + pento 0.12 mM	TTR + pento 0.48 mM	TTR + pento 0.96 mM
Amide I
Parallel β-sheet; (1621–1640 cm^−1)	51.6	31.3	16.9	14.7
Random Coil; (1640–1652 cm^−1)	1.7	3.4	4.2	4.0
α-helix; (1652–1666 cm^−1)	6.3	8.3	7.8	8.9
β-turns; (1666–1685 cm^−1)	21.3	33.4	36.6	33.9
Antiparallel β-sheets; (1600–1621 cm^−1); (1685–1700 cm^−1)	8.9; 10.1	13.4; 10.3	16.0; 18.5	20.2; 18.3
Amide II
Parallel β-sheet; (1490–1507 cm^−1)	45.0	27.6	6.4	5.2
Antiparallel β-sheet; (1507–1528 cm^−1)	0.14	12.1	35.2	32.6
α-helix; (1528–1550 cm^−1)	23.2	18.9	17.4	18.9
β-turns; (1550–1570 cm^−1)	25.3	25.5	21.6	20.17
Antiparallel β-sheets; (1570–1590 cm^−1)	6.3	15.9	19.3	23.2