User:Daniel Parrell/Sandbox 1
From Proteopedia
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==Structure== | ==Structure== | ||
===Hydrogen Bonding in the Channel=== | ===Hydrogen Bonding in the Channel=== | ||
| - | One of the defining features of aquaporins, and of Aquaporin 4 is the center <scene name='User:Daniel_Parrell/Sandbox_1/Channel_amino_acids_and_water/1'>Channel</scene>,its amino acids, and how it interacts, through hydrogen bonding,to drive water transport. The water molecules are held in the channel by the carboxyl oxygens of the amino acid <scene name='User:Daniel_Parrell/Sandbox_1/Carboxyl_side_chains/ | + | One of the defining features of aquaporins, and of Aquaporin 4 is the center <scene name='User:Daniel_Parrell/Sandbox_1/Channel_amino_acids_and_water/1'>Channel</scene>,its amino acids, and how it interacts, through hydrogen bonding,to drive water transport. The water molecules are held in the channel by the carboxyl oxygens of the amino acid <scene name='User:Daniel_Parrell/Sandbox_1/Carboxyl_side_chains/2'>residues</scene> Gly-93, Gly-94, His-95, and Ile-96, Gly-209, Ala-210, Ser-211, and Met-212. The spcific orientation of water in the channel is thought to be driven by a conserved sequence of amino acids called the <scene name='User:Daniel_Parrell/Sandbox_1/Npa_motif/1'>NPA motif</scene> (Asp-Pro-Ala) that is thought to hold the center water molecules in a specific orientation in the channel which defines the orientation of the other water molecules. |
Revision as of 21:47, 30 April 2011
Contents |
Aquaporin 4
Background
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The discovery of aquaporin channels was a brakthrough discovery relating to water transport in cells. Peter Agre's discovery of the aquaporin channel family, answered a key question that had stumped biochmesists and cell biologists for years. This was the question of how is water abe to transport across the hydrophobic lipid bilayer so efficiently? When experimentally determined, the rate of water transport is able to occure at a rate of about 10^9 molecules per second, this is many times the limit set by diffusion across the membrane. There are 13 known mammalian aquaporins. Each is expressed in different tissues, and serve different functions based of the common theme of water balance.
Aquaporin 4 (3GD8) is a part of the aquaporin family. Mostly expressed in brain astrocytes, it contains the same structural and functionla motifs typical of the aquaporins. The
Structure
Hydrogen Bonding in the Channel
One of the defining features of aquaporins, and of Aquaporin 4 is the center ,its amino acids, and how it interacts, through hydrogen bonding,to drive water transport. The water molecules are held in the channel by the carboxyl oxygens of the amino acid Gly-93, Gly-94, His-95, and Ile-96, Gly-209, Ala-210, Ser-211, and Met-212. The spcific orientation of water in the channel is thought to be driven by a conserved sequence of amino acids called the (Asp-Pro-Ala) that is thought to hold the center water molecules in a specific orientation in the channel which defines the orientation of the other water molecules.
