Table 2.

Summary of FTIR data for the sample bulk solutions of SAA_1–13 and its associated mutants. FTIR of the washed fibrils are also shown for samples that displayed helical bands on the FTIR spectra of their bulk solutions.

Preparation	Peptide†	FTIR (cm−1)‡
		amide III	amide II	amide I
Bulk Solution	SAA1–13	1230	1527	1626, 1697
	SAA1–13S5A	1230	1527	1628, 1697
	SAA1–13D12N	1230	1527	1626, 1697
	SAA1–13D12A	1230	1529	1626, 1697
	SAA1–13E9Q	1234, 1315	1547	1626, 1656, 1680, 1699
	SAA1–13E9A	1234, 1313	1545	1626, 1656, 1680, 1699
	SAA1–13R1Cit	1242	–	1624, 1658, 1681, 1697
	SAA1–13R1A	1242	–	1624, 1655, 1678, 1699
	SAA1–13S5A (no heparin)	1230, 1315	1527, 1547	1625, 1656, 1680, 1697
Washed Fibrils	SAA1–13E9Q	–	1527	1626, 1697
	SAA1–13E9A	–	1527	1626, 1697
	SAA1–13S5A (no heparin)	–	1527	1625, 1697

^†Samples were incubated with heparin except for the last entry.

^‡Amide I, II, and III peaks taken as the minima of the second-derivative spectra.

^§Amyloid morphology as deduced from the TEM data.