Sandbox Reserved 1165: Difference between revisions
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Many of the [https://en.wikipedia.org/wiki/Residue_(chemistry) residues] in the binding pocket that are in direct contact with the glucagon molecule are [https://en.wikipedia.org/wiki/Ion charged] or are [https://en.wikipedia.org/wiki/Chemical_polarity polar]. | Many of the [https://en.wikipedia.org/wiki/Residue_(chemistry) residues] in the binding pocket that are in direct contact with the glucagon molecule are [https://en.wikipedia.org/wiki/Ion charged] or are [https://en.wikipedia.org/wiki/Chemical_polarity polar]. | ||
[[Image:Screen Shot 2016-03-29 at 3.24.43 PM.png|(|):|400 px|right|thumb|'''Figure 4: Salt Bridge'''. The salt bridge is located on the intracellular side at the bottom of the protein, in relation to the orientation it holds within the cell membrane. It is made between residues Glu 406, Arg 173, and Arg 346, as labeled in the figure.]] | [[Image:Screen Shot 2016-03-29 at 3.24.43 PM.png|(|):|400 px|right|thumb|'''Figure 4: Salt Bridge'''. The salt bridge is located on the intracellular side at the bottom of the protein, in relation to the orientation it holds within the cell membrane. It is made between residues Glu 406, Arg 173, and Arg 346, as labeled in the figure.]] | ||
There are also many smaller residues on glucagon that support the bulky residues on the GCGR. These residues are located within the binding pocket of the 7TM. <ref name="Ligands">PMID: 21542831</ref> There are specific amino acid interactions that hold the helices of the 7TM in the closed conformation that maximizes [http://www.chemicool.com/definition/affinity.html affinity]. <ref name="Ligands">PMID: 21542831</ref> This includes the [https://en.wikipedia.org/wiki/Disulfide disulfide bond] between Cys 294 and Cys 224 that was mentioned earlier that serves to hold the ECL1 and ECL2 in the proper orientation. Additionally, the [https://en.wikipedia.org/wiki/Salt_bridge_%28protein_and_supramolecular%29 salt bridges] between Glu 406, Arg 173, and Arg 346, also mentioned earlier, hold the conformation together for higher affinity. <ref name="Ligands">PMID: 21542831</ref> Finally, alpha helical structure of the stalk is imperative to the affinity and binding of the glucagon. <ref name="Tips">PMID: 23863937</ref> | There are also many smaller residues on glucagon that support the bulky residues on the GCGR. These residues are located within the binding pocket of the 7TM (Figure 5). <ref name="Ligands">PMID: 21542831</ref> There are specific amino acid interactions that hold the helices of the 7TM in the closed conformation that maximizes [http://www.chemicool.com/definition/affinity.html affinity]. <ref name="Ligands">PMID: 21542831</ref> This includes the [https://en.wikipedia.org/wiki/Disulfide disulfide bond] between Cys 294 and Cys 224 that was mentioned earlier that serves to hold the ECL1 and ECL2 in the proper orientation. Additionally, the [https://en.wikipedia.org/wiki/Salt_bridge_%28protein_and_supramolecular%29 salt bridges] between Glu 406, Arg 173, and Arg 346, also mentioned earlier, hold the conformation together for higher affinity (Figure 4). <ref name="Ligands">PMID: 21542831</ref> Finally, alpha helical structure of the stalk is imperative to the affinity and binding of the glucagon. <ref name="Tips">PMID: 23863937</ref> | ||
