Sandbox Reserved 970: Difference between revisions

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To sum up, calcium pumps have two conformations, E1 and E2. These two conformations are characterized by different specificity for ion binding. When the pump is in the <scene name='60/604489/E1_state_3w5b/1'>E1 state</scene>, it has high calcium affinity and interacts with calcium at one side of the membrane. In the E2 state, the enzyme has a lower calcium affinity and that leads to the release of the ion at the opposite side. E1 has the calcium binding site oriented toward the cytoplasm. E2 has the calcium binding site oriented toward the lumen of the endoplasmic reticulum or toward the extracellular background<ref name="third">Thomas D.Pollard and William C. Earnshaw, - ''Membrane, structure and function'' - Cell Biology (second edition), p.133-136</ref>. The phosphorylated intermediate, E1 can phosphorylate ADP, whereas E2 can only react with water<ref>David H.MacLennan, William J.Rice and N. Michael Green, 1997 - ''The Mechanism of Ca2+ Transport by Sarco(Endo)plasmic Reticulum Ca2+-ATPases'' - The Journal of Biological Chemistry, p.272, 28815-28818, http://www.jbc.org/content/272/46/28815.full.html</ref>.

[[Image:Etat.jpg|center|]]

Sandbox Reserved 970: Difference between revisions

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Revision as of 12:16, 7 January 2015 view source Elodie Sévère (talk \| contribs) 61 edits No edit summary ← Older edit		Revision as of 12:28, 7 January 2015 view source Déborah Kreyenbihler (talk \| contribs) 62 edits No edit summary Newer edit →
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	To sum up, calcium pumps have two conformations, E1 and E2. These two conformations are characterized by different specificity for ion binding. When the pump is in the <scene name='60/604489/E1_state_3w5b/1'>E1 state</scene>, it has high calcium affinity and interacts with calcium at one side of the membrane. In the E2 state, the enzyme has a lower calcium affinity and that leads to the release of the ion at the opposite side. E1 has the calcium binding site oriented toward the cytoplasm. E2 has the calcium binding site oriented toward the lumen of the endoplasmic reticulum or toward the extracellular background<ref name="third">Thomas D.Pollard and William C. Earnshaw, - ''Membrane, structure and function'' - Cell Biology (second edition), p.133-136</ref>. The phosphorylated intermediate, E1 can phosphorylate ADP, whereas E2 can only react with water<ref>David H.MacLennan, William J.Rice and N. Michael Green, 1997 - ''The Mechanism of Ca2+ Transport by Sarco(Endo)plasmic Reticulum Ca2+-ATPases'' - The Journal of Biological Chemistry, p.272, 28815-28818, http://www.jbc.org/content/272/46/28815.full.html</ref>.		To sum up, calcium pumps have two conformations, E1 and E2. These two conformations are characterized by different specificity for ion binding. When the pump is in the <scene name='60/604489/E1_state_3w5b/1'>E1 state</scene>, it has high calcium affinity and interacts with calcium at one side of the membrane. In the E2 state, the enzyme has a lower calcium affinity and that leads to the release of the ion at the opposite side. E1 has the calcium binding site oriented toward the cytoplasm. E2 has the calcium binding site oriented toward the lumen of the endoplasmic reticulum or toward the extracellular background<ref name="third">Thomas D.Pollard and William C. Earnshaw, - ''Membrane, structure and function'' - Cell Biology (second edition), p.133-136</ref>. The phosphorylated intermediate, E1 can phosphorylate ADP, whereas E2 can only react with water<ref>David H.MacLennan, William J.Rice and N. Michael Green, 1997 - ''The Mechanism of Ca2+ Transport by Sarco(Endo)plasmic Reticulum Ca2+-ATPases'' - The Journal of Biological Chemistry, p.272, 28815-28818, http://www.jbc.org/content/272/46/28815.full.html</ref>.


			[[Image:Etat.jpg\|center\|]]