Sandbox Reserved 1613: Difference between revisions

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ABCG2 transports a variety of <scene name='83/832939/Mz29/1'>substrates</scene>, particularly flat, hydrophobic, and/or polycylic molecules. It is found in different biological membranes, such as the blood-brain barrier (BBB), blood-testis barrier, and the blood-placental barrier. It is thought to help protect those tissues and many others from cytotoxins. In addition to cytotoxin protection, ABCG2 secretes endogenous substrates in the adrenal gland, excretes toxins in the liver and kidneys, and regulates absorption of substrates.

This is only opened when the protein is shifted from its interior facing to exterior facing formation by the transfer of a phosphate off of an ATP. This causes a shift and transfer to the second binding site which is open to the extracellular matrix. The Fab-5D3 antigen binding fragment was found to stabilize the protein in its inward facing conformation which allowed for high resolution images of the protein to be taken in this conformation. Without Fab attached, the conformation of the protein was constantly in flux, transporting substrates out of the cell constantly. Fab was found to only stabilize ABCG2 on the extracellular side. Three important interactions between Fab fragments and ABCG2 were important to binding stability and favorability. This binding occurred at the <scene name='83/832939/El-3/1'>EL-3</scene> of ABCG2, which is the helices that stretches the furthest from the cell membrane. These interactions were two disulfide bonds, one intramolecularly and the other intermolecularly, and an n-<scene name='83/832939/Glycos_site/1'>glycosylation site</scene> at residue Asn-596

== Relevance ==

By utilizing certain binders (<scene name='83/832939/5d3-fab/2'>5D3</scene>), it is able to be stabilized for crystallographic imaging.<ref name="Taylor">PMID:28554189</ref> This has allowed researchers in the past decade to make advances based upon the greater understanding of its structure. Using these advances, inhibitors have been found to stop effluxion by ABCG2. Completely inhibiting this function, however, has residual effects on the excretory system. One such effect is decreased uric acid excretion in both the kidneys and the gut, which causes [https://en.wikipedia.org/wiki/Hyperuricemia hyperuricemia] . This results in an increased risk of uric acid crystal build-up, known as [https://en.wikipedia.org/wiki/Tophus tophi formation], which causes a type of arthritis known as [https://en.wikipedia.org/wiki/Gout gout] . Balancing the inhibition of ABCG2 will determine how to lessen these effects while continuing to combat cancer resistivity.<ref name="Cleophas">PMID:28461764</ref>

Sandbox Reserved 1613: Difference between revisions

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@@ Line 28: / Line 28: @@
 ABCG2 transports a variety of <scene name='83/832939/Mz29/1'>substrates</scene>, particularly flat, hydrophobic, and/or polycylic molecules. It is found in different biological membranes, such as the blood-brain barrier (BBB), blood-testis barrier, and the blood-placental barrier. It is thought to help protect those tissues and many others from cytotoxins. In addition to cytotoxin protection, ABCG2 secretes endogenous substrates in the adrenal gland, excretes toxins in the liver and kidneys, and regulates absorption of substrates.
 <ref name="Fetsch">PMID:15990223</ref>
- This is only opened when the protein is shifted from its interior facing to exterior facing formation by the transfer of a phosphate off of an ATP. This causes a shift and transfer to the second binding site which is open to the extracellular matrix. The Fab-5D3 antigen binding fragment was found to stabilize the protein in its inward facing conformation which allowed for high resolution images of the protein to be taken in this conformation. Without Fab attached, the conformation of the protein was constantly in flux, transporting substrates out of the cell constantly. Fab was found to only stabilize ABCG2 on the extracellular side. Three important interactions between Fab fragments and ABCG2 were important to binding stability and favorability. This binding occurred at the <scene name='83/832939/El-3/1'>EL-3</scene> of ABCG2, which is the helices that stretches the furthest from the cell membrane. These interactions were two disulfide bonds, one intramolecularly and the other intermolecularly, and an n-<scene name='83/832939/Glycos_site/1'>glycosylation site</scene> at residue Asn-596
 == Relevance ==
 By utilizing certain binders (<scene name='83/832939/5d3-fab/2'>5D3</scene>), it is able to be stabilized for crystallographic imaging.<ref name="Taylor">PMID:28554189</ref> This has allowed researchers in the past decade to make advances based upon the greater understanding of its structure. Using these advances, inhibitors have been found to stop effluxion by ABCG2. Completely inhibiting this function, however, has residual effects on the excretory system. One such effect is decreased uric acid excretion in both the kidneys and the gut, which causes [https://en.wikipedia.org/wiki/Hyperuricemia hyperuricemia] . This results in an increased risk of uric acid crystal build-up, known as [https://en.wikipedia.org/wiki/Tophus tophi formation], which causes a type of arthritis known as [https://en.wikipedia.org/wiki/Gout gout] . Balancing the inhibition of ABCG2 will determine how to lessen these effects while continuing to combat cancer resistivity.<ref name="Cleophas">PMID:28461764</ref>