Biology Reference
In-Depth Information
(
Figure 13.3
). Each has a smooth hydrophobic surface that interacts with acyl chains of the
membrane phospholipids. The other surface is polar, being dominated by (
OH) groups
(3 for cholate and 2 for deoxycholate). A cylinder is formed with the membrane integral
protein forming the core, surrounded by a ring of phospholipids and finally a second ring
e
(a)
-
O
C
HO
HO
O
HYDROPHOBIC
SURFACE
HYDROPHILIC
SURFACE
HO
(b)
-
O
O
-
C
HO
HO
O
OH
OH
O
O
HO
HO
OH
OH
HO
OH
OH
HO
O
O
C
O
-
O
O
-
PHOSPHOLIPID
BILAYER
PHOSPHOLIPID
BILAYER
CHOLATE
PROTEIN
CHOLATE
FIGURE 13.3
Mechanism by which cholate solubilizes an integral membrane protein. (The structure of cholate
is shown in
Figure 13.1
.) Panel (a) is a cartoon drawing of cholate demonstrating its hydrophilic surface and its
hydrophobic surface. Panel (b) shows how cholate may extract a plug from the membrane that contains an integral
protein and phospholipids.
