Potassium Channel: Difference between revisions

Line 1:

[[Image:&&&|150px|left]]      [[Potassium ~~channels~~]] control the electric potential across cell membranes by selectively catalyzing the diffusion of K+ ions down their electrochemical gradient.<ref name="Zhou">PMID: 11689936</ref> K+ Channels extend across the cell membrane, a 40 Angstrom thick lipid bilayer across which ions cannot pass without assistance.<ref name="Doyle">PMID: 9525859</ref> Potassium homeostasis is crucial for nearly all living cells, but is particularly important for the correct function of neurons. Neurons produce electrical impulses known as action potentials, to initiate cellular communication processes like neurotransmitter release or activate intercellular processes muscle contraction. At the onset of an action potential, sodium ions flood across the plasma membrane of neurons via sodium channels. This influx of sodium ions causes the polarity of the plasma membrane to reverse, inactivating sodium channels and activating potassium channels. Potassium channels subsequently open allowing the selective diffusion of K+ ions across the plasma membrane, returning the membrane polarity to neutral. After the action potential has passed, channels recreate the high potassium concentration within the cell in preparation for the next stiumulus.<ref>PMID:12721618</ref> Mutations in voltage-gated potassium channel KCNC3 have been linked with neurodevelopmental disorders and neurodegeneration.<ref>PMID: 16501573</ref>

[[Image:&&&|150px|left]]      [[Potassium channel]]'''s''' control the electric potential across cell membranes by selectively catalyzing the diffusion of K+ ions down their electrochemical gradient.<ref name="Zhou">PMID: 11689936</ref> K+ Channels extend across the cell membrane, a 40 Angstrom thick lipid bilayer across which ions cannot pass without assistance.<ref name="Doyle">PMID: 9525859</ref> Potassium homeostasis is crucial for nearly all living cells, but is particularly important for the correct function of neurons. Neurons produce electrical impulses known as action potentials, to initiate cellular communication processes like neurotransmitter release or activate intercellular processes muscle contraction. At the onset of an action potential, sodium ions flood across the plasma membrane of neurons via sodium channels. This influx of sodium ions causes the polarity of the plasma membrane to reverse, inactivating sodium channels and activating potassium channels. Potassium channels subsequently open allowing the selective diffusion of K+ ions across the plasma membrane, returning the membrane polarity to neutral. After the action potential has passed, channels recreate the high potassium concentration within the cell in preparation for the next stiumulus.<ref>PMID:12721618</ref> Mutations in voltage-gated potassium channel KCNC3 have been linked with neurodevelopmental disorders and neurodegeneration.<ref>PMID: 16501573</ref>

Potassium channels possess two traits that are seemingly mutually exclusive. Firstly, potassium channels have exquisite selectivity, with an amazing 10,000 fold selectivity for K+ ions over sodium ions. Considering the only difference by which potassium ions can be differentiated from sodium ions is potassium ions’ 1.33 Angstrom Pauling radius vs. Sodium’s .95 Angstrom radius, the selectivity of potassium channels is remarkable.<ref name="Doyle"/> Second, despite its remarkable selectivity, potassium channels allow for the transfer of K+ ions across the cell membrane at a rate of nearly 108 per second, nearly at the diffusion rate limit.<ref name="Long">PMID: 18004376</ref> Potassium channels are able to achieve these remarkable feats due to its amazing structural architecture contains several remarkable features which not only can sense the voltage potential across a membrane, but also selectively ferry K+ ions without any outside energy expenditure.

Line 12:

Line 13:

      Overall, Potassium channels are remarkable structures that allow for near diffusion limit transfer of molecules with sub-angstrom specificity. Our understanding of the structure of Potassium Channels has opened up the potential for [[Pharmaceutical drugs|Therapeutic Intervention]] into Potassium channel related diseases.

</StructureSection>

==Additional Structures of Potassium Channels==

For Additional Structures, See: [[Potassium%2C_Calcium_Channel#Available_structures|Potassium Channels]]

Potassium Channel: Difference between revisions

Navigation menu

Page actions

Page actions

Personal tools

Navigation

Search

Tools

@@ Line 1: / Line 1: @@
-[[Image:&&&|150px|left]]&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; [[Potassium channels]] control the electric potential across cell membranes by selectively catalyzing the diffusion of K<sup>+</sup> ions down their electrochemical gradient.<ref name="Zhou">PMID: 11689936</ref> K<sup>+</sup> Channels extend across the cell membrane, a 40 Angstrom thick lipid bilayer across which ions cannot pass without assistance.<ref name="Doyle">PMID: 9525859</ref> Potassium homeostasis is crucial for nearly all living cells, but is particularly important for the correct function of neurons. Neurons produce electrical impulses known as action potentials, to initiate cellular communication processes like neurotransmitter release or activate intercellular processes muscle contraction. At the onset of an action potential, sodium ions flood across the plasma membrane of neurons via sodium channels. This influx of sodium ions causes the polarity of the plasma membrane to reverse, inactivating sodium channels and activating potassium channels. Potassium channels subsequently open allowing the selective diffusion of K<sup>+</sup> ions across the plasma membrane, returning the membrane polarity to neutral. After the action potential has passed, channels recreate the high potassium concentration within the cell in preparation for the next stiumulus.<ref>PMID:12721618</ref> Mutations in voltage-gated potassium channel KCNC3 have been linked with neurodevelopmental disorders and neurodegeneration.<ref>PMID: 16501573</ref>
+<StructureSection load='' size='500' side='right' caption='Structure of the Potassium Channel' scene=''>
+[[Image:&&&|150px|left]]&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; [[Potassium channel]]'''s''' control the electric potential across cell membranes by selectively catalyzing the diffusion of K<sup>+</sup> ions down their electrochemical gradient.<ref name="Zhou">PMID: 11689936</ref> K<sup>+</sup> Channels extend across the cell membrane, a 40 Angstrom thick lipid bilayer across which ions cannot pass without assistance.<ref name="Doyle">PMID: 9525859</ref> Potassium homeostasis is crucial for nearly all living cells, but is particularly important for the correct function of neurons. Neurons produce electrical impulses known as action potentials, to initiate cellular communication processes like neurotransmitter release or activate intercellular processes muscle contraction. At the onset of an action potential, sodium ions flood across the plasma membrane of neurons via sodium channels. This influx of sodium ions causes the polarity of the plasma membrane to reverse, inactivating sodium channels and activating potassium channels. Potassium channels subsequently open allowing the selective diffusion of K<sup>+</sup> ions across the plasma membrane, returning the membrane polarity to neutral. After the action potential has passed, channels recreate the high potassium concentration within the cell in preparation for the next stiumulus.<ref>PMID:12721618</ref> Mutations in voltage-gated potassium channel KCNC3 have been linked with neurodevelopmental disorders and neurodegeneration.<ref>PMID: 16501573</ref>
 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Potassium channels possess two traits that are seemingly mutually exclusive. Firstly, potassium channels have exquisite selectivity, with an amazing 10,000 fold selectivity for K<sup>+</sup> ions over sodium ions. Considering the only difference by which potassium ions can be differentiated from sodium ions is potassium ions’ 1.33 Angstrom Pauling radius vs. Sodium’s .95 Angstrom radius, the selectivity of potassium channels is remarkable.<ref name="Doyle"/> Second, despite its remarkable selectivity, potassium channels allow for the transfer of K<sup>+</sup> ions across the cell membrane at a rate of nearly 10<sup>8</sup> per second, nearly at the diffusion rate limit.<ref name="Long">PMID: 18004376</ref> Potassium channels are able to achieve these remarkable feats due to its amazing structural architecture contains several remarkable features which not only can sense the voltage potential across a membrane, but also selectively ferry K<sup>+</sup> ions without any outside energy expenditure.
@@ Line 12: / Line 13: @@
 &nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Overall, Potassium channels are remarkable structures that allow for near diffusion limit transfer of molecules with sub-angstrom specificity. Our understanding of the structure of Potassium Channels has opened up the potential for [[Pharmaceutical drugs|Therapeutic Intervention]] into Potassium channel related diseases.
+</StructureSection>
 ==Additional Structures of Potassium Channels==
 For Additional Structures, See: [[Potassium%2C_Calcium_Channel#Available_structures|Potassium Channels]]