Table 1.

Ranges of the C_α, C_β, and C_γ chemical shifts for the most abundant amino acids in elastin

Assignment	α-helix (ppm)	β-sheet/turn (ppm)	Random coil (ppm)
Cβ-Ile	—	—	11.2a
Cγ-Val	—	—	18.4–19.2b
Cβ-Ala	14.6–17.65	17.39–21.49	16.06–18.62
Cβ-Ile	34.75–37.05	36.18–40.24	34.50–38.64
Cβ-Leu	38.59–41.00	40.09–44.31	38.47–42.32
Cβ-Phe	35.72–38.70	38.10–41.59	35.77–39.73
Cβ-Pro	28.54–30.71	29.37–31.77	29.21–31.19
Cβ-Thr	65.96–68.35	67.01–71.23	66.76–69.75
Cβ-Val	28.97–30.51	30.32–33.90	29.22–32.74
Cα-Ala	49.00–54.18	47.90–51.31	49.21–52.78
Cα-Gly	42.50–46.31	41.50–44.69	42.20–44.86
Cα-Leu	54.59–57.05	51.05–53.69	51.36–54.94
Cα-Phe	57.21–61.01	53.32–56.54	53.26–58.30
Cα-Pro	62.71–64.87	59.87–62.31	60.51–63.09
Cα-Val	62.87–66.01	57.43–60.77	57.85–62.52

Shown are the maximum and minimum chemical shifts observed in previous studies (45–49,68). The maximum value was determined from the largest reported value plus its uncertainty and the minimum value from the smallest reported value minus its uncertainty. All values except those of Asakura et al. (45) were adjusted for the tetramethylsilane scale by subtracting 1.7 ppm (68), since the original references used 4,4-dimethyl-4-silapentane-1-sulfonic acid as the standard.

^aValues when the amino acid is followed by alanine.

^bValues when the amino acid is followed by proline.