Selectivity against Passing Ions or an Electrochemical Gradient

Selectivity against Passing Ions or an Electrochemical Gradient 

Removal of water and the fixing of a specific conformation of glycerol in the GlpF channel are also energetically costly. However, the structure specifically matches the donor plus acceptor and amphipathic nature of each of a series of C—OH groups, replacing the hydration shell in water by a precise match within the channel. 

The Various Contributions to Rejection of Proton Conductance 

To analyze the basis for water conductance of GlpF we determined the crystal structure of GlpF in the absence of glycerol (Tajkhorshid et al., 2002). This structure at 2.7 A resolution showed that water molecules form a line through the channel in which each water molecule is a hydrogen bond donor to one of the eight carbonyls that line the channel, 

---

XII. Selectivity against Passing Ions or an Electrochemical Gradient. 309... 

---