Peptide Nanotubes: A Crystallographic Approach
117
Hydrophobic layer
Hydrophilic layer
Fig. 17 The crystal of AF viewed along the c-axis shows the formation of alternate hydrophobic
layer. Water molecules () are part of the hydrophilic layer
Table 9 Hydrogen-bond parameters for L -Alanyl-α, β-dehydrophenylalanine (AF)
D (donor) A(acceptor) DLA
(Å)
HLA (Å)
D-HLA (°)
Symmetry Code
C7
N2
3.091
2.48
124
x, y, z
N1
O2 W
2.780
2.05
137
−x + 1, +y + 1/2, −z + 1
C2
O1 W
3.652
2.91
135
x + 1, +y + 1, +z
N1
O1 W
3.071
2.33
141
−x + 1, +y + 1/2, −z
N1
O1 W
2.865
1.99
169
x + 1, +y + 1, +z
N1
O3
3.002
2.32
134
−x + 1, +y + 1/2, −z
C1
O2
3.396
2.66
132
x + 1, +y, +z
N2
O2
2.869
2.07
155
x + 1, +y, +z
C2
O1
3.121
2.51
122
x + 1, +y, +z
O1 W
O1
3.068
–
–
x, +y − 1, +z
O1 W
O1
3.142
–
–
−x + 1, +y − 1/2, −z
O1 W
O3
2.847
–
–
−x + 1, +y − 1/2, −z
O1 W
O2 W
3.221
–
–
x, +y − 1, +z − 1
O1 W
O2 W
3.354
–
–
−x, +y − 1/2, −z + 1
O1 W
O2 W
3.460
–
–
−x + 1, +y − 1/2, −z + 1
O2 W
O2
2.745
–
–
−x, +y + 1/2, −z + 1
O2 W
O3
2.783
–
–
−x + 1, +y + 1/2, −z + 1