Sandbox Reserved 1717: Difference between revisions

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=== Binding ===

In its resting state, VKOR is in its <scene name='90/904322/Open_conformation/1'>open conformation</scene>. The Vitamin K epoxide enters through the <scene name='90/904322/Tunnel/5'>isoprenyl-chain tunnel</scene>. The tunnel is located between TM2 (dark) and TM3 (light). The ketones on the VK epoxide bind to <scene name='90/904322/Vko_binding/1'>Asn80 and Tyr139</scene> on VKOR. With Vitamin K epoxide bound, the cysteines of VKOR are partially oxidized, and concurrently reduce the substrate. A disulfide bond then forms between Cys51 and Cys132, resulting in the closed conformation. This leaves the sulfur on Cys43 and the sulfur on Cys135 protonated. The available hydrogens on these cysteines are utilized in reducing the epoxide. First, the free sulfur on Cys43 attacks Cys51 to form a new disulfide bond. With the loss of hydrogen from Cys43 in the formation of the new disulfide bond, an electron transfer is made to VKO. Next, the sulfur on Cys132 and the sulfur on Cys135 form a new disulfide bond. The hydrogen that was present on Cys135 is lost in the formation of the disulfide bond, allowing for an electron transfer to the oxygen of the epoxide. With these cysteine pairs formed, VKOR is left in an open conformation. The end products are Vitamin K/quinone and water.

In its resting state, VKOR is in its <scene name='90/904322/Open_conformation/1'>open conformation</scene>. The Vitamin K epoxide enters through the <scene name='90/904322/Tunnel/6'>isoprenyl-chain tunnel</scene>. The tunnel is located between TM2 (dark) and TM3 (light). The ketones on the VK epoxide bind to <scene name='90/904322/Vko_binding/1'>Asn80 and Tyr139</scene> on VKOR. With Vitamin K epoxide bound, the cysteines of VKOR are partially oxidized, and concurrently reduce the substrate. A disulfide bond then forms between Cys51 and Cys132, resulting in the closed conformation. This leaves the sulfur on Cys43 and the sulfur on Cys135 protonated. The available hydrogens on these cysteines are utilized in reducing the epoxide. First, the free sulfur on Cys43 attacks Cys51 to form a new disulfide bond. With the loss of hydrogen from Cys43 in the formation of the new disulfide bond, an electron transfer is made to VKO. Next, the sulfur on Cys132 and the sulfur on Cys135 form a new disulfide bond. The hydrogen that was present on Cys135 is lost in the formation of the disulfide bond, allowing for an electron transfer to the oxygen of the epoxide. With these cysteine pairs formed, VKOR is left in an open conformation. The end products are Vitamin K/quinone and water.

Sandbox Reserved 1717: Difference between revisions

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@@ Line 54: / Line 54: @@
 [[Image:Vitaminkquinone.PNG|200 px|left|thumb|Figure 5. Vitamin K Quinone structure]] [[Image:Vitaminkhydroquinone.PNG|200 px|right|thumb|Figure 6. Vitamin K Hydroquinone structure]]
 === Binding ===
-In its resting state, VKOR is in its <scene name='90/904322/Open_conformation/1'>open conformation</scene>. The Vitamin K epoxide enters through the <scene name='90/904322/Tunnel/5'>isoprenyl-chain tunnel</scene>. The tunnel is located between TM2 (dark) and TM3 (light). The ketones on the VK epoxide bind to <scene name='90/904322/Vko_binding/1'>Asn80 and Tyr139</scene> on VKOR. With Vitamin K epoxide bound, the cysteines of VKOR are partially oxidized, and concurrently reduce the substrate. A disulfide bond then forms between Cys51 and Cys132, resulting in the closed conformation. This leaves the sulfur on Cys43 and the sulfur on Cys135 protonated. The available hydrogens on these cysteines are utilized in reducing the epoxide. First, the free sulfur on Cys43 attacks Cys51 to form a new disulfide bond. With the loss of hydrogen from Cys43 in the formation of the new disulfide bond, an electron transfer is made to VKO. Next, the sulfur on Cys132 and the sulfur on Cys135 form a new disulfide bond. The hydrogen that was present on Cys135 is lost in the formation of the disulfide bond, allowing for an electron transfer to the oxygen of the epoxide. With these cysteine pairs formed, VKOR is left in an open conformation. The end products are Vitamin K/quinone and water.
+In its resting state, VKOR is in its <scene name='90/904322/Open_conformation/1'>open conformation</scene>. The Vitamin K epoxide enters through the <scene name='90/904322/Tunnel/6'>isoprenyl-chain tunnel</scene>. The tunnel is located between TM2 (dark) and TM3 (light). The ketones on the VK epoxide bind to <scene name='90/904322/Vko_binding/1'>Asn80 and Tyr139</scene> on VKOR. With Vitamin K epoxide bound, the cysteines of VKOR are partially oxidized, and concurrently reduce the substrate. A disulfide bond then forms between Cys51 and Cys132, resulting in the closed conformation. This leaves the sulfur on Cys43 and the sulfur on Cys135 protonated. The available hydrogens on these cysteines are utilized in reducing the epoxide. First, the free sulfur on Cys43 attacks Cys51 to form a new disulfide bond. With the loss of hydrogen from Cys43 in the formation of the new disulfide bond, an electron transfer is made to VKO. Next, the sulfur on Cys132 and the sulfur on Cys135 form a new disulfide bond. The hydrogen that was present on Cys135 is lost in the formation of the disulfide bond, allowing for an electron transfer to the oxygen of the epoxide. With these cysteine pairs formed, VKOR is left in an open conformation. The end products are Vitamin K/quinone and water.