Sandbox Reserved 969: Difference between revisions

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The nature of the ligands is '''carbonyl-hydroxyl'''.
The nature of the ligands is '''carbonyl-hydroxyl'''.


== The Filter Selectivity ==
== '''The Filter Selectivity''' ==


The filter is defined by a highly conserved amino acid sequence T(63)VGDG(67) that’s why the channel is selective for some cations like K+ or Na+. The selectivity filter has the same conformation in low K+/high Na+ or high K+/low Na+ concentrations. So the concentration does not impact the conformation of the filter but it can adopt 2 different structures : a conductive state and a non conductive state. In fact, some hydrogen bonds are important for the stability of the NaK selectivity filter and the balance between the 2 structures. For example, an hydrogen bond between residues Asp-66 and Asn-68 stabilize the non conductive state whereas an hydrogen bond between Asp-66 and Tyr-55 stabilize the conductive state. The change between the 2 structures are very fast.  
The filter is defined by a highly conserved amino acid sequence T(63)VGDG(67) that’s why the channel is selective for some cations like K+ or Na+. The selectivity filter has the same conformation in low K+/high Na+ or high K+/low Na+ concentrations. So the concentration does not impact the conformation of the filter but it can adopt 2 different structures : a conductive state and a non conductive state. In fact, some hydrogen bonds are important for the stability of the NaK selectivity filter and the balance between the 2 structures. For example, an hydrogen bond between residues Asp-66 and Asn-68 stabilize the non conductive state whereas an hydrogen bond between Asp-66 and Tyr-55 stabilize the conductive state. The change between the 2 structures are very fast.