Sandbox Reserved 1412
From Proteopedia
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The protein's main structure is <scene name='77/777732/Helices/1'>7 transmembrane alpha helices</scene>. The inside of the molecule is hydrophilic, which allows for protons to be transported without issue <ref>Terango, M. Bacteriorhodopsin. https://collab.its.virginia.edu/access/content/group/f85bed6c-45d2-4b18-b868-6a2353586804/2/Ch09_Terango_M_Bacteriorhodopsin-_-/Ch09_Terango_M_Bacteriorhodopsin_Bacteriorhodopsin.html (accessed Feb 12, 2018).</ref>. | The protein's main structure is <scene name='77/777732/Helices/1'>7 transmembrane alpha helices</scene>. The inside of the molecule is hydrophilic, which allows for protons to be transported without issue <ref>Terango, M. Bacteriorhodopsin. https://collab.its.virginia.edu/access/content/group/f85bed6c-45d2-4b18-b868-6a2353586804/2/Ch09_Terango_M_Bacteriorhodopsin-_-/Ch09_Terango_M_Bacteriorhodopsin_Bacteriorhodopsin.html (accessed Feb 12, 2018).</ref>. | ||
| - | <p>Light energy and protonation of the molecule leads to a complex system of isomerization that releases a proton outside of the membrane. The <scene name='77/777732/Ligand_v2/1'>retinal</scene> is at the center of the protein and is bound to the alpha helices. In bacterial rhodopsin, the retinal functions as a proton pump by a conformation from all trans to cis-13. The<scene name='77/777732/Cis-13/1'> 13th carbon</scene> goes from cis to trans when the retinal is hit by light, and this change pumps protons out of the cell <ref>PMID:24364740</ref>.</p> Due to the bonding patterns and placement of the retinal molecule, when the conformational change occurs the entire protein changes to move protons <ref>Terango, M. Bacteriorhodopsin. https://collab.its.virginia.edu/access/content/group/f85bed6c-45d2-4b18-b868-6a2353586804/2/Ch09_Terango_M_Bacteriorhodopsin-_-/Ch09_Terango_M_Bacteriorhodopsin_Bacteriorhodopsin.html (accessed Feb 12, 2018).</ref>. | + | <p>Light energy and protonation of the molecule leads to a complex system of isomerization that releases a proton outside of the membrane. The <scene name='77/777732/Ligand_v2/1'>retinal</scene> is at the center of the protein and is bound to the alpha helices. In bacterial rhodopsin, the retinal functions as a proton pump by a conformation from all trans to cis-13. The<scene name='77/777732/Cis-13/1'> 13th carbon</scene> goes from cis to trans when the retinal is hit by light, and this change pumps protons out of the cell <ref>PMID:24364740</ref>.</p> Due to the bonding patterns and placement of the retinal molecule, when the conformational change occurs the entire protein changes to move protons <ref>Terango, M. Bacteriorhodopsin. https://collab.its.virginia.edu/access/content/group/f85bed6c-45d2-4b18-b868-6a2353586804/2/Ch09_Terango_M_Bacteriorhodopsin-_-/Ch09_Terango_M_Bacteriorhodopsin_Bacteriorhodopsin.html (accessed Feb 12, 2018).</ref>.. |
<p>Bacteriorhodopsin has multiple key residues in its structure: one end of <scene name='77/777732/Lys216_and_asp85/1'>Lys-216 and Asp-85</scene> bond to water molecules to increase stability and alter the shape of the molecule during the conformational changes. | <p>Bacteriorhodopsin has multiple key residues in its structure: one end of <scene name='77/777732/Lys216_and_asp85/1'>Lys-216 and Asp-85</scene> bond to water molecules to increase stability and alter the shape of the molecule during the conformational changes. | ||
| - | While deprotonated, the molecule is much less stable. Therefore the lost proton is quickly replaced, allowing the mechanism to be more efficient even though it sends protons against the concentration gradient. </p> | + | While deprotonated, the molecule is much less stable. Therefore the lost proton is quickly replaced, allowing the mechanism to be more efficient even though it sends protons against the concentration gradient <ref>Terango, M. Bacteriorhodopsin. https://collab.its.virginia.edu/access/content/group/f85bed6c-45d2-4b18-b868-6a2353586804/2/Ch09_Terango_M_Bacteriorhodopsin-_-/Ch09_Terango_M_Bacteriorhodopsin_Bacteriorhodopsin.html (accessed Feb 12, 2018).</ref>. </p> |
Revision as of 03:17, 14 February 2018
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| This Sandbox is Reserved from January through July 31, 2018 for use in the course HLSC322: Principles of Genetics and Genomics taught by Genevieve Houston-Ludlam at the University of Maryland, College Park, USA. This reservation includes Sandbox Reserved 1311 through Sandbox Reserved 1430. |
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Contents |
Rhodopsin
Bacteriorhodopsin is a photoreceptor protein found in Archaea. When in the presence of light energy and protons, the protein undergoes a five-part conformational change and pumps protons out of the cell, creating an electrochemical gradient with a more negative intracellular environment [1] [2].
Structure
The protein's main structure is . The inside of the molecule is hydrophilic, which allows for protons to be transported without issue [3].
Light energy and protonation of the molecule leads to a complex system of isomerization that releases a proton outside of the membrane. The is at the center of the protein and is bound to the alpha helices. In bacterial rhodopsin, the retinal functions as a proton pump by a conformation from all trans to cis-13. The goes from cis to trans when the retinal is hit by light, and this change pumps protons out of the cell [4].
Due to the bonding patterns and placement of the retinal molecule, when the conformational change occurs the entire protein changes to move protons [5]..Bacteriorhodopsin has multiple key residues in its structure: one end of bond to water molecules to increase stability and alter the shape of the molecule during the conformational changes. While deprotonated, the molecule is much less stable. Therefore the lost proton is quickly replaced, allowing the mechanism to be more efficient even though it sends protons against the concentration gradient [6].
Function
Bacteriorhodopsin reacts in the presence of photons to This proton pump is used to create a gradient that can be used for things like ATP synthesis. Water is used to bind to the protein; no other outside molecules are necessary.
References
- ↑ Ernst OP, Lodowski DT, Elstner M, Hegemann P, Brown LS, Kandori H. Microbial and animal rhodopsins: structures, functions, and molecular mechanisms. Chem Rev. 2014 Jan 8;114(1):126-63. doi: 10.1021/cr4003769. Epub 2013 Dec 23. PMID:24364740 doi:http://dx.doi.org/10.1021/cr4003769
- ↑ Terango, M. Bacteriorhodopsin. https://collab.its.virginia.edu/access/content/group/f85bed6c-45d2-4b18-b868-6a2353586804/2/Ch09_Terango_M_Bacteriorhodopsin-_-/Ch09_Terango_M_Bacteriorhodopsin_Bacteriorhodopsin.html (accessed Feb 12, 2018).
- ↑ Terango, M. Bacteriorhodopsin. https://collab.its.virginia.edu/access/content/group/f85bed6c-45d2-4b18-b868-6a2353586804/2/Ch09_Terango_M_Bacteriorhodopsin-_-/Ch09_Terango_M_Bacteriorhodopsin_Bacteriorhodopsin.html (accessed Feb 12, 2018).
- ↑ Ernst OP, Lodowski DT, Elstner M, Hegemann P, Brown LS, Kandori H. Microbial and animal rhodopsins: structures, functions, and molecular mechanisms. Chem Rev. 2014 Jan 8;114(1):126-63. doi: 10.1021/cr4003769. Epub 2013 Dec 23. PMID:24364740 doi:http://dx.doi.org/10.1021/cr4003769
- ↑ Terango, M. Bacteriorhodopsin. https://collab.its.virginia.edu/access/content/group/f85bed6c-45d2-4b18-b868-6a2353586804/2/Ch09_Terango_M_Bacteriorhodopsin-_-/Ch09_Terango_M_Bacteriorhodopsin_Bacteriorhodopsin.html (accessed Feb 12, 2018).
- ↑ Terango, M. Bacteriorhodopsin. https://collab.its.virginia.edu/access/content/group/f85bed6c-45d2-4b18-b868-6a2353586804/2/Ch09_Terango_M_Bacteriorhodopsin-_-/Ch09_Terango_M_Bacteriorhodopsin_Bacteriorhodopsin.html (accessed Feb 12, 2018).
