Mesoscopic models of lipid bilayers and bilayers with embedded ...

106 Mesoscopic model for lipid bilayers with embedded proteins
d L (r) [Å]
45.0
35.0
25.0
15.0
0.0 20.0 40.0 60.0 80.0
(a) NP=4
d L (r) [Å]
r [Å]
45.0
35.0
25.0
∆d=−10
∆d=−6
∆d=−1
∆d= 8
∆d=17
∆d=26
d L (r) [Å]
45.0
35.0
25.0
15.0
0.0 20.0 40.0 60.0 80.0
r [Å]
(c) NP=43
15.0
0.0 20.0 40.0 60.0 80.0
∆d=−10
∆d=−6
∆d=−1
∆d= 8
∆d=17
∆d=26
(b) NP=7
r [Å]
∆d=−10
∆d=−6
∆d=−1
∆d= 8
∆d=17
∆d=26
Figure 7.3: Lipid bilayer hydrophobic thickness profiles, dL(r) as function of the distance r
from the protein surface, for different hydrophobic mismatch ∆d = ˜dP − d o L, and for the three
protein sizes NP=4, 7 and 43. The data refer to the reduced temperature T ∗ =0.7, which is well
above the main-transition temperature of the pure system (T ∗ m=0.425). The calculated pure
lipid bilayer hydrophobic thickness at T ∗ =0.7 is d o L =(23.6±0.2) ˚A. The symbols for ∆d refer to
the following estimated values of the protein hydrophobic length: the open circle to ˜dP=14 ˚A
(negative ∆d), the open triangle to ˜dP=18 ˚A (negative ∆d), the plus to ˜dP=23 ˚A (∆d ≈ 0), the full
triangle to ˜dP=32 ˚A (positive ∆d), the full circle to ˜dP=41 ˚A (positive ∆d), and the full diamonds
to ˜dP=50 ˚A (positive ∆d).