Table 2: Amino acid grouping (Levitt-6), Amino acid grouping (Someya-7).
(a)

NonpolarPolar

-HelixA, C, L, ME, H, K, Q, R
-StrandF, I, V, W, YT
TurnG, PD, N, S

(b)

NonpolarPolar

-HelixA, L, ME, H, K, Q, R
-StrandF, I, V, W, YT
TurnG, PD, N, S
CysteineC