Sandbox Reserved 470: Difference between revisions

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'''[[Glyceraldehyde-3-phosphate Dehydrogenase]]'''

<Structure load='3gpd' size='400' frame='true' align='right' caption='Glyceraldehyde-3-phosphate Dehydrogenase' scene='Insert optional scene name here' />(abbreviated as GAPDH or the less common G3PDH) (EC 1.2.1.12) ~37kDa catalyzes the sixth step of glycolysis, a reversible cytosolic process in eukaryotes which involves the breakdown of glucose for energy and carbon molecules. Along with its role in glycolysis and gluconeogenesis, recent research has determined that GAPDH is actually a multifunctional protein, as it has numerous defined, non-metabolic functions involved in multiple subcellular processes including transcription activation, ER to Golgi transportation, transcriptional control of histone gene expression, nuclear membrane fusion, neuronal initiation of apoptosis, recognizing fraudulently incorporated nucleotides in DNA, and maintaining telomere structures. Research also ~~shoes~~ that it possibly has a direct involvement in cellular phenotype of human neurodegenerative disorders, especially those characterized by expansion of [CAG repeats].

<Structure load='3gpd' size='400' frame='true' align='right' caption='Glyceraldehyde-3-phosphate Dehydrogenase' scene='Insert optional scene name here' />(abbreviated as GAPDH or the less common G3PDH) (EC 1.2.1.12) ~37kDa catalyzes the sixth step of [glycolysis], a reversible cytosolic process in [eukaryotes] which involves the breakdown of glucose for energy and carbon molecules. Along with its role in glycolysis and [gluconeogenesis], recent research has determined that GAPDH is actually a multifunctional protein, as it has numerous defined, non-metabolic functions involved in multiple subcellular processes including [transcription] activation, ER to Golgi transportation, transcriptional control of histone [gene expression], nuclear membrane fusion, neuronal initiation of [apoptosis], recognizing fraudulently incorporated nucleotides in DNA, and maintaining [telomere] structures. Research also shows that it possibly has a direct involvement in cellular phenotype of human [neurodegenerative] disorders, especially those characterized by expansion of [CAG repeats].

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'''Role in Glycolysis:'''

[[Image:GAPDH_PGK-rxn.gif]]

In three coupled steps, GAPDH catalyzes the conversion of glyceraldyhyde-3-phosphate at carbon 1 to 1,3-bisphosphoglycerate (1,3-BPG), by combining ~~phosphorylatin~~ with oxidation in an overall ~~energonic~~ reaction (ΔG°'=+6.3 kJ/mol (+1.5 kcal/mol)). First, the oxidation of glyceraldyhyde-3-phosphate to D-glycerate 1,3-bisphosphate takes place, in which an aldehyde is converted to carboxylic acid ((ΔG°'=-50 kJ/mol (-12 kcal/mol))and NAD+, an important co-factor and ligand found bound to the <scene name='Sandbox_Reserved_470/Active_site_gapdh/1'>active site</scene> of GAPDH, is simultaneously reduced endergonically to NADH. This oxidation reaction is required for the initiation of the second reaction because it is highly exergonic and thus drives the endergonic second reaction ((ΔG°'=+50 kJ/mol (+12 kcal/mol)). In the second reaction a molecule of inorganic phosphate is transferred to a GAP intermediate to form a product with a high potential to transfer phosphates, 1,3-bisphosphoglycerate. Without GAPDH's use of covalent catalysis in the second step, the energy barrier of the reaction would be too high and the reaction would be too slow for living organisms.

*The Steps:

:In three coupled steps, GAPDH catalyzes the conversion of [glyceraldyhyde-3-phosphate] at carbon 1 to [1,3-bisphosphoglycerate] (1,3-BPG), by combining phosphorylation with oxidation in an overall [endergonic] reaction (ΔG°'=+6.3 kJ/mol (+1.5 kcal/mol)). First, the oxidation of glyceraldyhyde-3-phosphate to D-glycerate 1,3-bisphosphate takes place, in which an aldehyde is converted to carboxylic acid ((ΔG°'=-50 kJ/mol (-12 kcal/mol))and NAD+ ([Nicotinamide adenine dinucleotide]), an important co-factor and [ligand] found bound to the <scene name='Sandbox_Reserved_470/Active_site_gapdh/1'>active site</scene> of GAPDH, is simultaneously reduced endergonically to NADH. This oxidation reaction is required for the initiation of the second reaction because it is highly [exergonic] and thus drives the endergonic second reaction ((ΔG°'=+50 kJ/mol (+12 kcal/mol)). In the second reaction a molecule of inorganic phosphate is transferred to a GAP intermediate to form a product with a high potential to transfer phosphates, 1,3-bisphosphoglycerate. Without GAPDH's use of covalent catalysis in the second step, the energy barrier of the reaction would be too high and the reaction would be too slow for living organisms.

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'''Other roles:'''

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 '''[[Glyceraldehyde-3-phosphate Dehydrogenase]]'''
-<Structure load='3gpd' size='400' frame='true' align='right' caption='Glyceraldehyde-3-phosphate Dehydrogenase' scene='Insert optional scene name here' />(abbreviated as GAPDH or the less common G3PDH) (EC 1.2.1.12) ~37kDa catalyzes the sixth step of glycolysis, a reversible cytosolic process in eukaryotes which involves the breakdown of glucose for energy and carbon molecules.  Along with its role in glycolysis and gluconeogenesis, recent research has determined that GAPDH is actually a multifunctional protein, as it has numerous defined, non-metabolic functions involved in multiple subcellular processes including transcription activation, ER  to Golgi transportation, transcriptional control of histone gene expression, nuclear membrane fusion, neuronal initiation of apoptosis, recognizing fraudulently incorporated nucleotides in DNA, and maintaining telomere structures.  Research also shoes that it possibly has a direct involvement in cellular phenotype of human neurodegenerative disorders, especially those characterized by expansion of [CAG repeats].
+<Structure load='3gpd' size='400' frame='true' align='right' caption='Glyceraldehyde-3-phosphate Dehydrogenase' scene='Insert optional scene name here' />(abbreviated as GAPDH or the less common G3PDH) (EC 1.2.1.12) ~37kDa catalyzes the sixth step of [glycolysis], a reversible cytosolic process in [eukaryotes] which involves the breakdown of glucose for energy and carbon molecules.  Along with its role in glycolysis and [gluconeogenesis], recent research has determined that GAPDH is actually a multifunctional protein, as it has numerous defined, non-metabolic functions involved in multiple subcellular processes including [transcription] activation, ER  to Golgi transportation, transcriptional control of histone [gene expression], nuclear membrane fusion, neuronal initiation of [apoptosis], recognizing fraudulently incorporated nucleotides in DNA, and maintaining [telomere] structures.  Research also shows that it possibly has a direct involvement in cellular phenotype of human [neurodegenerative] disorders, especially those characterized by expansion of [CAG repeats].
 ----
 '''Role in Glycolysis:'''
 [[Image:GAPDH_PGK-rxn.gif]]
-In three coupled steps, GAPDH catalyzes the conversion of glyceraldyhyde-3-phosphate at carbon 1 to 1,3-bisphosphoglycerate (1,3-BPG), by combining phosphorylatin with oxidation in an overall energonic reaction (ΔG°'=+6.3 kJ/mol (+1.5 kcal/mol)).  First, the oxidation of glyceraldyhyde-3-phosphate to D-glycerate 1,3-bisphosphate takes place, in which an aldehyde is converted to carboxylic acid ((ΔG°'=-50 kJ/mol (-12 kcal/mol))and NAD+, an important co-factor and ligand found bound to the <scene name='Sandbox_Reserved_470/Active_site_gapdh/1'>active site</scene> of GAPDH, is simultaneously reduced endergonically to NADH.  This oxidation reaction is required for the initiation of the second reaction because it is highly exergonic and thus drives the endergonic second reaction ((ΔG°'=+50 kJ/mol (+12 kcal/mol)).  In the second reaction a molecule of inorganic phosphate is transferred to a GAP intermediate to form a product with a high potential to transfer phosphates, 1,3-bisphosphoglycerate.  Without GAPDH's use of covalent catalysis in the second step, the energy barrier of the reaction would be too high and the reaction would be too slow for living organisms.
+*The Steps:
+:In three coupled steps, GAPDH catalyzes the conversion of [glyceraldyhyde-3-phosphate] at carbon 1 to [1,3-bisphosphoglycerate] (1,3-BPG), by combining phosphorylation with oxidation in an overall [endergonic] reaction (ΔG°'=+6.3 kJ/mol (+1.5 kcal/mol)).  First, the oxidation of glyceraldyhyde-3-phosphate to D-glycerate 1,3-bisphosphate takes place, in which an aldehyde is converted to carboxylic acid ((ΔG°'=-50 kJ/mol (-12 kcal/mol))and NAD+ ([Nicotinamide adenine dinucleotide]), an important co-factor and [ligand] found bound to the <scene name='Sandbox_Reserved_470/Active_site_gapdh/1'>active site</scene> of GAPDH, is simultaneously reduced endergonically to NADH.  This oxidation reaction is required for the initiation of the second reaction because it is highly [exergonic] and thus drives the endergonic second reaction ((ΔG°'=+50 kJ/mol (+12 kcal/mol)).  In the second reaction a molecule of inorganic phosphate is transferred to a GAP intermediate to form a product with a high potential to transfer phosphates, 1,3-bisphosphoglycerate.  Without GAPDH's use of covalent catalysis in the second step, the energy barrier of the reaction would be too high and the reaction would be too slow for living organisms.
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 '''Other roles:'''