User:Cameron Evans/Sandbox 1: Difference between revisions

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The

<scene name='User:Cameron_Evans/Sandbox_1/Gtp_n_helix/1'>GTP binds </scene> between the active site of the monomer and the <color=red> pivot helix </~~color~~>. It is thought that GTP causes negative regulation of GluDH by increasing the enzyme's affinity for the product to the extent that the release of the product is the rate limiting step of the overall reaction.

<scene name='User:Cameron_Evans/Sandbox_1/Gtp_n_helix/1'>GTP binds </scene> between the active site of the monomer and the <font color='red'>pivot helix </font>. It is thought that GTP causes negative regulation of GluDH by increasing the enzyme's affinity for the product to the extent that the release of the product is the rate limiting step of the overall reaction.

When the enzyme is highly saturated, the enzyme has been found to form an "abortive complex" that is the cofactor and the reagent locked in a non-catalytic conformation. Upon the binding of a positive regulator, like GDP or ADP, the protein is thought to be forced into the open conformation, driving the reaction is allowed to completion. ADP has also been shown to decrease the affinity of the enzyme to its products.

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=====Dinucleotides=====

The NAD(P)(H) coenzyme is has also been shown to <scene name='User:Cameron_Evans/Sandbox_1/2nd_cofactor/3'>bind in the same general region the other allosteric regulators bind</scene> - that is, between the pivot helix ~~(RED)~~ and the active site. Furthermore, this binding site appears to bind NAD(H) with ten times the affinity as NADP(H). As might be expected, the binding of the reduced coenzyme inhibits oxidative deamination, and the binding of the oxidized form promotes deamination.

The NAD(P)(H) coenzyme is has also been shown to <scene name='User:Cameron_Evans/Sandbox_1/2nd_cofactor/3'>bind in the same general region the other allosteric regulators bind</scene> - that is, between the <font color='red'>pivot helix </font> and the active site. Furthermore, this binding site appears to bind NAD(H) with ten times the affinity as NADP(H). As might be expected, the binding of the reduced coenzyme inhibits oxidative deamination, and the binding of the oxidized form promotes deamination.

During reductive amination, NADPH is an inhibitor at pH 8, but not at pH7. Furthermore, NADPH binding is greatly enhanced in the presence of glutamate, where it inhibits the enzyme; however, the enhanced binding observed in the presence of ketoglutarate is not coupled with inhibition.

@@ Line 84: / Line 84: @@
 The
-<scene name='User:Cameron_Evans/Sandbox_1/Gtp_n_helix/1'>GTP binds </scene> between the active site of the monomer and the <color=red> pivot helix </color>. It is thought that GTP causes negative regulation of GluDH by increasing the enzyme's affinity for the product to the extent that the release of the product is the rate limiting step of the overall reaction.
+<scene name='User:Cameron_Evans/Sandbox_1/Gtp_n_helix/1'>GTP binds </scene> between the active site of the monomer and the <font color='red'>pivot helix </font>. It is thought that GTP causes negative regulation of GluDH by increasing the enzyme's affinity for the product to the extent that the release of the product is the rate limiting step of the overall reaction.
 When the enzyme is highly saturated, the enzyme has been found to form an "abortive complex" that is the cofactor and the reagent locked in a non-catalytic conformation. Upon the binding of a positive regulator, like GDP or ADP, the protein is thought to be forced into the open conformation, driving the reaction is allowed to completion. ADP has also been shown to decrease the affinity of the enzyme to its products.
@@ Line 91: / Line 91: @@
 =====Dinucleotides=====
-The NAD(P)(H) coenzyme is has also been shown to <scene name='User:Cameron_Evans/Sandbox_1/2nd_cofactor/3'>bind in the same general region the other allosteric regulators bind</scene> - that is, between the pivot helix (RED) and the active site. Furthermore, this binding site appears to bind NAD(H) with ten times the affinity as NADP(H). As might be expected, the binding of the reduced coenzyme inhibits oxidative deamination, and the binding of the oxidized form promotes deamination.
+The NAD(P)(H) coenzyme is has also been shown to <scene name='User:Cameron_Evans/Sandbox_1/2nd_cofactor/3'>bind in the same general region the other allosteric regulators bind</scene> - that is, between the <font color='red'>pivot helix </font> and the active site. Furthermore, this binding site appears to bind NAD(H) with ten times the affinity as NADP(H). As might be expected, the binding of the reduced coenzyme inhibits oxidative deamination, and the binding of the oxidized form promotes deamination.
 During reductive amination, NADPH is an inhibitor at pH 8, but not at pH7. Furthermore, NADPH binding is greatly enhanced in the presence of glutamate, where it inhibits the enzyme; however, the enhanced binding observed in the presence of ketoglutarate is not coupled with inhibition.